The slower a bullet is traveling the faster the twist needs to be to get the same number of RPM's for stabilization.
So if you are shooting subsonic ammo, you will need a faster twist for the same bullet length and weight.
Over stabilizing a bullet will only hurt the accuracy on a precision rifle, you won't notice it on a PS90, but under stabilizing as you know will cause keyholes and, if shooting suppressed, baffle or endcap strikes.
I've been lurking on and off for about a year and a half now. I spend most of my time on silencertalk.
I hope my first post was helpful.