Just to double-check: after the UI change in UE5, HammUEr (and all my plugins, really) only has the menu option at the bottom of the Window list, which definitely should exist?
I was... annoyed that they changed up the whole toolbar button code with the UI changes and just broke it, but not the menu option, and never really... bothered to try bringing it back, since nobody really seemed to be missing it? (I think there might also not have been like, an example of the New Correct Way in the first version of 5.0, but that might just be my faulty memory)
Sorry.
Hopefully that unblocks you, at least.
If not, we have... deeper problems.
Maybe I'll re-add it down the line somewhere.
Also: HammUEr doesn't really touch any of the UE BSP stuff (because it has always been a massive pain), everything gets imported as static meshes