I just decided to take a section of a Vavoom hub I had been working on and dump it into GZDoom, just to see how it would look.
That's when I noticed that the dynamic lights just act as though the 3DFloors aren't even there.
I'm not sure if this carries over to the other 3D floor types or not. I plan on moving this over to GZDoom, so I'm going to convert them to the EDGE/Legacy type regardless, but I had noticed that you were curious about how it played different Vavoom levels, so I thought I'd post it nonetheless.
Some screenshots that better illustrate the problem: