I would think the 20x may be too much in some cases. You’d probably be fine with the 12x, but I’d wait for someone who shoots PRS to chime in. Also I second Strelok. Been using it for years.
I have a trick for this that I've never seen anyone use besides myself....
I have no problem at all running at 24X because I do this...
Most PRS shooters get used to running at reduced magnification to widen the field of view so they can find the target faster.
The reduced magnification however costs them in precise target acquisition.
Some guys will run a red dot on a pic rail on the top scope ring, but then they have to head bob up and down between the scope and red dot to find the target. It also increases the vertical height of the rifle making it harder in confined spaces.
So my solution requires the addition of a scope ring picatinny rail that only mounts to the scope and I rotate to about 9:00 or 9:30
To that I mount a short riser block and to that I mount a Vortex red dot.
The riser block increases the distance from the scope far enough that I can see the red dot with my left eye while looking through the magnified optic with my right eye.
I don't need to head bob to find the target, I just focus on left eye to acquire, then concentrate on my right to shoot.
It would be nice if someone produced a proper setup for this where we could shim the height of the red dot to precisely align with the individual shooters space between the eyes. But this system seems to work pretty good even if it's not the exact right spacing.
Here's a pic from my CZ452 set up as described.