I do feel that “This is the way” to go in my place without turning it upside down. Otherwise I need to keep bringing the speakers one meter or more into the room…
I am strongly inclined towards 21i + an appropriate subwoofer at the moment, based on what I have heard so far in my room. If they looked nicer it would have been a foregone conclusion… 
Try some tweeters made from Beskar 
I currently run the PMC 26’s in my room, at times they sound stunning even with my modest front end but when I substituted them for my friends 21’s the 21’s just seemed to work so well with the room.
Been giving the speaker swap lots of thought and still haven’t made any progress!
I think the main reason being I will never be able to afford to purchase another pair of speakers at the level of my 26’s, so do I invest in a better front end to see if that works, my heart says keep them my head says “you know you need to down size” the joys of Hifi 
this is the way.
I used 20.21 speakers in my system before the Vivid’s they were good - but for some reason…they excited my room giving me ill defined bass around 57hz. I managed to dial this out with DSP with a very steep filter… it worked. They sounded really good. However the Vivid was in a different league…before going down the PMC route…check out the Jern 11. I have just seen these at Audio T they look excellent and weigh about 20lbs!!! These are infinite baffle try and get an audition…they are around £1300…ps the later PMC’s have much better bass drive units - so there may be better control.
I would keep them and get a better front end … defo…(only if there is no boom)…if 26’s boom then be careful the 21’s maybe the way to go…the 26 is a superb speaker…in my opinion if I had the space …it would be on my shortlist…I think I might update the 202…
A very relevant question, however the room in which the music is played influences the sound, some rooms far more than others, and expecting wonderful music in a bad room, or perfect results from a perfect system in a compromised room, is simply expecting the impossible. Of course the human brain is so adaptable that it can like it, even learn to love it, while people spending huge amounts might convince themselves it is nirvana, but without addressing any room limitations that might exist no system can sound as good as it potentially could, whether just a bit less so in a pretty good room, or far from it in a bad room. Luckily many systems can perform pretty well in a wide range of rooms, but some rooms can be a real challenge: I have had hifi systems in many rooms, and whilst undoubtedly all could have improved with judicious room treatment (about whionly ever once had e.g. one particular pair of speakers (IMF RSPM) in 4 quite different rooms without issue, then in the 5th the sound was awful. Unliveable with. Eventually I found a layout that worked very well - remarkably so - though it took some time and effort, and the assistance of REW software, and a complete rearrangement of the room, whereas in all previous rooms I had simply assigned speaker and listening positions using very loose guidelines, and been happy.
If that was a system that satisfied you, then perhaps yes.
But for me, getting the speakers right is key to a satisfying system - and in my case it was finding my first IMFs well over 40 years ago - probable nearest modern equivalent is the PMC Twentyfive26 - that turned my system from good music playing to something on a higher plane: still good music playing but more deeply satisfying (pun not intended). Personally I don’t understand how so many people with otherwise expensive hifi systems seem content with what I feel are quite limiting speakers, but of course each to her or his own. If I were in your position not yet having found the speakers for me, I’d go speaker auditioning spreading the net as wide as possible, listening to speakers at the higher end of what I can afford, not limiting to new, until I hear ones that truly satisfy. I wouldn’t worry about amp - that can be chosen to suit the speakers, not the other way round, though I’d take my own amp just to be sure to check it can drive them tolerably well. If a confirmatory home demo isn’t possible I’d want to take my existing speakers to give a baseline for my ears in the room.
Was it PRO 9TL speakers ?
IMF TLS50ii. But from memory the Pro 9TL, also transmission line, subscribed to similar principles and, although I never heard a pair, I wouldn’t be surprised if there was considerable similarity in sound presentation.
I actually built a pair of Pro 9 TL’s many years ago and now currently use PMC twenty26’s which provide a very similar performance, if you are attacked to the transmission line it sort of stays with you.
Indeed it does! My upgrades after the first were all transmission line.
You seem undecided but the B&W speakers seem to match your room, set up and ears best so wouldn’t rush into anything.
Infact I’d embrace the KISS philosophy and just enjoy them.
Good luck.
That’s right. The problem is though that once one has heared more details coming out of another loudspeaker that those simple BW’s do only tick the boxes for musicality and not other hifi aspects like detail soundstage imaging and whatever other loudspeakers can do.
Ignorance bliss
The Fact3 has two 3 position switches on the back to + or - bass and treble settings, precisely for room situations that may need tweaking. I tried mine briefly with my Nait2 (pending recap), not yet with my Nova, but my room is the opposite to yours in that it’s a bit over damped and eats bass up.
This is the way… until I make up my mind with no rush. But my friend has taken over the BWs for in her place and enjoys them too much to return them, so I need to grab a second pair from the second hand market first 
Or potentially a pair of 685 S2 to compare while I am at it. I can always sell them without loss afterwards.
Not quite beskar, but you cannot get closer I guess 
. Interesting proposition nevertheless. I could try to audition them if I find them in Belgium and add a data point in my list of auditioned speakers.
Indeed, based on what I read, the bass driver was improved going from twenty to twenty5. And then the tweeter was refined when going from twenty5 to twenty5i. As I have listened to the last two, it does make a huge difference. twenty5 was almost unbearable in terms of listening fatigue for me.
I’ll share some speaker measurements in my room later on for some extra discussions.
That’s how one can get crazy, yes. I replaced my Dynaudios (EMITs) with 25.21i’s back in 2021, in a period when lockdown was lifted a bit, and I could audition again… And I recognize the choice overload, I think I was lucky that way there weren’t that much options for auditions during covid. I was quite interested in hearing the D2R’s too although their were off limits budget-wise, but I simply couldn’t unless willing to travel across the country (Holland, but still). My room mode has a 50Hz bump at listening position (and is much smaller than yours) which I could correct a bit during a ‘REW weekend’ enlessly shuffling the subwoofer (and the phase settings). Or… I just lean forward by 40 cm.
Despite the lack of options, I fell in love with the 25.21i’s so much that I told the dealer to not bother on setting up any B&W’s (which were next on the agenda), and I walked out with the demo pair. They had already run for 100 hrs so ready to go for home use. Strangely Impulsive - yes. Sort of how falling in love can make you go irrational. I did notice almost the same qualities you listed. Lively and detailed rather than Polite and analytical, they do pull your attention. I have never regretted it though, the only negative I would list is that they don’t really work at low volume, that is to me where the musicality gets overshadowed by the detail retrieval. I use them in my study, and I find that I need to switch the system off because they just don’t work as ‘background easy listening’ - they just break my concentration while at work.
I had PMC 20.21"s they were excellent…and I know exactly what you mean…the only thing I would be inclined to do ultimately is use better crossover parts…and mount the crossovers in an external box. Having said all that they are very very good…enjoy…I used mine on a full fat 500 system…and they were never embarrassed…they just got better and better in a small room phenominal
I previously had PMC Twenty 23s. Now I’ve got Kudos Titan 606 speakers.
These brands both work well with Naim and because of their type, you can get them closer to the rear wall.
For interest, I used to have a DACMagic 100 DAC but replaced it when it started to have issues. I tried Topping, which was a similar size, but ended up getting a Khadas Tone Board, which was altogether a much better DAC.
DG…
I see you have Dynaudio C1s firing across a small to mid sized room and powered by a Supernait.
On the basis of our experience trying to drive them down a 21foot long room when powered by NAP135s, I’d be very surprised if your system doesn’t boom, badly.
First, the C1 Platinums need a much more controlling power amp to drive them. Secondly, they need a LOT of room behind them to stop booming. Even placing them 1 metre out into the room and driving them with Naim monoblocks , they still boomed for us.
As others have suggested, you may need to start by changing speakers.
Best regards, BF