I've released a new beta with the fix (see first post). While technically it's not a bug (it's a mod side one) and it's a minor thing i've pushed a fix since there must be a fallback default for the sound class gender when it's not properly defined and that must be male not other since that's the default value for the gender cvar (doomguy it's not an object). So please tell Impie it's a problem with the mod itself.
Of course the dither shader had to go so no more intel fixed versions (not needed anymore).
This delayed beta is in sync (is that term even correct?) with GZ master as of 11/29 to clarify things.
I could not port the recent SSE optimizations to the poly renderer (and the poly renderer is very important in LZDoom).
There was a crash in resolutions > 640 with "removed the 8x8 block drawing code from softpoly" related to sky caps, of course i could try to fix that. But then "change DrawSpanOpt32 to render a scanline in multiple steps" causes a black screen problem with broken geometry in the menu, it only works after starting the software renderer first after engine launch. That's why it requires "change the software renderer to render to a DSimpleCanvas like the old D3D9 target did. Then use the drawer threads to memcpy the result to the PBO" which itself requires some things in "added a software scene drawer to the GL renderer".
Just in case someone is interested, as usual any hints/help would be appreciated.
Also i've pushed a lot of stuff for the legacy build, looks like Graf is working on the engine full time. Does he even sleep?

So i'm getting close but still not there.