HW website makes the claims of mid-20 ftlb. It is essentially a gasram powered HW80.
Certainly the hw90 can give 25ftlb, but how accurately and for how long?
Most people seem to find that about 20ftlb is the maximu ideal power.

If something goes wrong, it should be something that most good gunsmiths could fix, so I doubt it would need to go back to Germany.