atmasphere, name or show me a link for three to consider, I am not against the technology but so far none really seem worthy to pursue. I did contact one mfg. recently on their brand new product... no response
@sayas If you want something that has the best of what class A has to offer I can think of three just off the top of my head
AGD
And ours (as if you didn't expect that).
GaNFETs have been around well over ten years at this point.
Finally, were I to make a change to D it would make sense to have speakers that were developed with the technology...
I run my class D amps on horn speakers made by Classic Audio Loudspeakers. They are intended for low power class A tube amps but work fine with the class Ds. I don't think you need to have a speaker as you describe; if it works with a class A amp it will work with class D too.