Why?
Just for the fun of it!
I very much doubt that adding PowerUp emulation can be sorted under "fun".
We talk here about rather obscure pieces of hardware that AFAIK aren't very well documented, and with heaploads of corner case issues.
As you clearly said there are lots of Windows/Linux/Mac tools and games 1000% percent better than Amiga, so if you are into Amiga emulation, it is just for enjoyment, nostalgia or something along the lines
And where does PowerUp fit in here? I bought a CSPPC in 1997 for way too much money, and a CVPPC quite soon after, yes there were a few games and apps, but I dont think any of them justifies the work. My PPC was quite clearly mostly used to accelerate media decoding, on UAE this is not a problem anyhow.
If you really think it makes sense, then go ahead and do it yourself.
