I have a pair of ProAc D30RS speakers for some time now and have had no issues. Not sure why you are concerned about the ribbon tweeter. If there is a problem I would contact my dealer and sure it could be repaired/replaced if there was a problem.
…perhaps I have just been lucky but have never had a problem with any of my speakers including tweeters that I can recall. A couple of problems with electronic components have occurred over the years and they were sorted out through the dealer.
I’ve got a pair of D2rs and it’s not a thought that had ever crossed my mind any more than any other driver in a speaker. Not sure what special care would involve. They just work.
I’ve just got a pair of Neats with ribbon tweeters and wasn’t expecting any problems re maintenance. Like all speakers they’ll probably need a bit of dusting occasionally, and if there’s any little curious fingers just put the covers on.
My brother-in-law came over one day and had an app on his phone which played a tone which could be increased or lowered in pitch, with the idea that you played it through a system to find out the range of your hearing.
Well, he plugged it into my system and we whacked the volume up to see how high we could hear. The ribbon tweeters on my Neat Elite SEs promptly glowed red and then burnt out. Lol. A relatively inexpensive repair to get Bob to replace them for me, but lesson learned!
I am on my third pair of Proacs, all with ribbon tweeters. Our original D40R demo needed a ribbon repair and we did it ourselves with the right tools, which the dealer sent us with the new part. I think they would have been available at the hardware store if needed. No problem at all.