I looked and didn't see the gas port size on PSA uppers. That would be helpful to know to predict how over gassed the carbine will be.
You ought to call or email to find out the port size and report back here.
As you probably know, most off the shelf rifles and uppers are way over gassed (even without a suppressor) since the manufacturer cannot control ammo selection or rifle maintenance and lube habits of the end user. Over gassed, to a point, equals fewer issues related to cheap, weak ammo, a dirty or dry rifle. Even so, odds are the rifle will function ok with the fixed gas block.
Benefits of an adjustable gas block include reduced and smoother perceived recoil, less wear on the rifle, less gas in the face and a rifle that runs cleaner and cooler. Brass last longer with gas adjusted too, since an over gassed condition is hard on brass, bolt and extractor. (Shooting suppressed puts crud back into the receiver, more with too much gas but still enough that more frequent cleaning is required, even with gas tamped down via an adjustable gas block or bolt carrier.)
I am a lefty and I have one 16" 5.56 with a non adjustable gas block that is over gassed even without a suppressor. Other than the harsher recoil compared to my rifles or uppers that have adjustable gas, it shoots fine and the gas is tollerable. I think I must be less sensitive to gas than some guys, It never really bothers me.
Fwiw, I agree with gkc5150, try it with the fixed block and see how it goes.
Hope this helps.
JPK