Should post something in the next few days. I've been eliminating bugs and streamlining code. Example showing multiple shadows and dynamic lights in action with an fps around 200 at a high resolution with everything turned on:
https://i.postimg.cc/mgcpKT6f/more-shadows.gif
What's done: dual shadows and wall shadows, dynamic sector lighting, added dynamic lighting, colored lighting, dimness settings, "ghost" lights, and floor reflections. There are many performance settings that can tweak what gets shadows and lights, how strong those are, how far away they are, what kind they are, etc.
What's not done: while I analyze flats I don't analyze wall textures. I've opted for a dynamic approach instead of static lights attached to textures that never change the shadow mapping. This is simpler, faster, more compatible with any mod or game, and doesn't kill framerates. It's not as pretty, I suppose, but it works with anything.
I just keep finding bugs... approaching final stages of alpha testing.