Err no, is the simple answer to that.
Naim has never done it before because simply there amp’s couldn’t do it.
Having the mono amp near each speaker certainly work’s very well.
You can get away with running much longer xlr’s to the amp versus speaker cables.
The amp’s will be fine sitting close behind the speaker, and have less forces going into them compared to the amp’s sitting in front off the speaker’s even if further away from the speakers. As most speaker’s drive forward and not backwards.
Plus you have just removed 2 powered unit’s from the rack, and power amp’s normally are the units with the biggest power draw, and transformers in them, so having them away from the main rack is certainly only going to be better.
If i was going to buy the 350’s this is how i would use them.
Go for that,if you think that there is less vibration and microphony close to the speakers,than far away from them.
I’d have thought placing them on the floor near each speaker would be a good option. Also, it simplifies the rack issues.
Totally agree so many tasty advantages…
Do that. I did with my 135s. Who actually came up with Brains and Brawn nonsense anyway. As long as the power is far enough away from the sensitive bits if it sounds right it is right. 
When I swapped from L4 to Radikal, I had to move it. The Lingo made no hum, but the Radikal did. I ended up with it on the floor under the shelves so it is as far as poss from LP12 and 52 and Superline.
I also found that I should not plug it into the dedicated power supply (cable from the meter) with the other hifi boxes- I use that for the Naim’s and plug the Radikal into the standard ring main socket on the wall.
The result is worth the bother.
I don’t think it’s quite as simple as that. I don’t use any Linn equipment these days, but I’m aware that Chord, who also use bult in switching supplies, recommend that you keep them away from amps using toroidal transformers.
Keep the power supply as far away as you can from the kit and then just to mess with your head, we will send the audio out feed back to the power supply. Obviously makes complete sense.
The fact naim has gone back to power supplies in the same box as the 135 tells you something about separate power supplies for amp’s, it will be interesting to see what way they go with the new 500 amp
You would think gone for good. If you can tame the Statement transformer in the S1 preamp……then trickle down to the rest of the range?
More than likely gazza, but maybe they will need to try and justify the much more expensive kit with 2 boxes, even if it’s not needed.
But everyone else seems to do it ok these days, and you only really get the separate power supplies on amp’s in the very high end or when size/weight comes into it.
As you mention, there are benefits of doing it this way but I can’t agree with the above statement. High frequencies may be directional, but the lower you go down in the frequencies, the more things become omnidirectional. Low bass radiates 360 degrees around the speaker, Naim are all about isolation, so plunking an amp beside a speaker is probably not the best option in their eyes. While there are benefits to both methods, I don’t doubt people wanting their big mono’s being shown off upfront, is done many times just for aesthetics.
I have my own stacking order trouble/decision points too as I’m adding more boxes now, hoping to get some insight on this. As I’m considering a Fraim setup, how should 332/333/300/250 stack be? I thought of preamp on top, then 333, then 250, then 300. Any recommendations on another combination? @Richard.Dane , any advice on this?
I think my dealer probably knows better than you, and I think you are just assuming a lot of things without really knowing the facts. You didn’t answer when I asked you to back up your statements with expertise/evidence, so I just assume you’re making it up on baseless assumptions.
Wouldn’t you isolate them on two Fraim bases?
How many Fraim stacks? Two would be better than one here
Hi Richard. Any thoughts on the original query?
I’ve not tried the NAP350, but would probably treat both units like a PS.
Or like an old style NAP, such as a 250 or a 135… 
Well trust your dealer,
I trust my own experience.
I see. So you’ve had amps near your speakers that caused problems. Understood.