Windows 10 is fine, it doesn't need to settle down a bit
From my experience and widely reported from many others, pretty much all software that worked on Windows 8.1 works on Windows 10 Technical Preview. Speccy is the only exception on my PC.
FWIW, I used to work in a well known software company 20 years ago and we would work feverishly to make sure our products worked before the first beta was released of any Microsoft OS. And we took pride getting in getting the job done. And yes as a MS partner, we did have access to builds before public betas. Perhaps Piriform is not in that position, but there's no excuse not to give it a try now!