[DiapDealer]

I take that back. At least on my VM, setting QSG_RHI_BACKEND to opengl causes the included opengl32sw.dll to be used. At least that's what it says in the logs when I set QSG_INFO=1

But it's still being used in some way on my Windows VM regardless of the QSG_RHI_BACKEND value. Sigil crashes without it. I just can't see it in the very tired Dependency Walker any more.