i gave this a go, but unfortunately it didn't seem to change anything. i did notice something interesting, though: the aforementioned ELFCLASS32 errors are actually being ignored by steam according to logs, and they all come from gameoverlayrenderer.so? half-life still fails to launch with GL forwarded, but i can't see any other stdout lines that would reflect a crash reason.
just to verify on the side: it's not documented on the wiki, but i assume the flow is
cmake -DBUILD_THUNKS=True ., followed by ninja guest-libs, then finally cp Guest/lib*-guest.so /usr/share/fex-emu/GuestThunks/?in any case, having any combination of
asound, drm, or WaylandClient enabled causes steamwebhelper to consistently fail to launch, and GL forwarding results in these issues running half-life on my setup.