They put it into vanilla?

With next update, yes. Already in RC.

Wasn't sure about the muzzle, if I should let it take the 5.56 suppressors, which seems to be common IRL practice on the PS90. Making abstraction of the mount/suppressor compatibility, obviously. So I haven't touched the muzzle config. Thoughts ?

Apparently they can even fit .22 rated suppressors. I am not sure if this is an off case (in which case we could support it) or a general one (in which case we would have to make it more detailed, which isn't worth it).

.22, 5.56, and 5.7 suppressors would all have the same diameter hole, so the only problems would be how it attaches and if the suppressor is strong enough to container the pressure from the blast.

I wouldn't want to use a suppressor meant for .22LR on a 5.7 or 5.56 gun unless it was robust.

I think that 7.62x39mm vz58 is missing, also CZ805 with its original magwell can accept only it's own mags and G36 mags, so I am not sure if it's worth forking or just straight up using G36 class.

Well do CZ805 magazines also fit into G36? Then I'd say just reuse it.

This is what I am not sure of, sadly...
(I found some comment under one article, that Bren mags don't work with G36)

What do magazines have to do with this PR ? Wrong thread ?

Dedmen asked me to report is here, sorry if wrong thread.

What do magazines have to do with this PR ?

Both are about vanilla :D