Just going over the max recommended won't suddenly create a deadly creature if you just go a bit over.

Tower recommends up to a .55 engine for the Revolver. Figure the OS.55AX is 18.5oz with muffler and your engine is???

Go much over on the power plant weight and you'll need to move the battery back and maybe a servo or two (if you can) to keep the CG where recommended without adding more dead weight. The important thing is to keep the CG at the recommended location.

That model is pretty fast with a 46 on it. So adding some weight isn't going to turn it into a completely different animal.

Just try not to go over 1.5X the wing loading and keep the CG where it's supposed to be.

The CG is a bit more important with heavier than recommended models. Moving a CG forward (weight or not) reduces the tail's effectiveness. Make the plane heavier and that forward CG can defeat the tail that's already had some power taken away.