I've found Mate and IceWM to be the most stable. Xfce has issues, KDE plasma has issues, and Lxqt has issues in my testing. I've also noticed window drawing is laggy on my dual 2ghz G5. Doesn't matter if the compositor is turned on or off. Better with it off, but still not perfect. Probably due to the nvidia geforce fx5200 (but its fine in ubuntu/debian). As it's a rolling release it seems not much is really tested. If it builds it gets added to the repo. I've run across a few packages that just crash on startup (gnome-twitch for example). I've had to reinstall 3 times now after updating, then powering down. Upon reboot, same issue. Black or white screen, fans on high. Sometimes i can get it back by booting the old 4.4 kernel, but sometimes even that doesn't work. Sometimes resetting the PRAM fixes it, others it doesn't. I've finally got a stable system, and i will no longer do full system updates. I locked my current kernel in place, and if i need to update a package, say firefox, i just install that with it's deps, and nothing more. So far so good. Luckily that machine also has ubuntu on it so i've been able to retrieve any documents, music etc from a broken Void before reinstalling. Oddly on my 32bit systems, it's been rock solid. Go figure.
The only real downside to you using the musl build, is that you have no access to arcticfox, interweb, or spiderweb. All of which display properly with no graphical glitches. I only use firefox for 2 websites that give the others the finger. Epiphany only renders 3/4 of a page with the entire right side cut off on both my 32 and 64bit installs, and it's slow as molasses anyway.
Cheers