The Doom engine didn't have diffusing lights, only ambient light on a per-sector basis. Ray tracing doesn't make sense in-engine unless you change how the lighting as a whole works.

In the OG engine, you can't have a lit floor and a dark ceiling, for example. And objects in a dark area can't be lit up by a light source from a bright area. The transition between lighting zones are hard cutoffs, and the maps were designed with this feature in mind.

If you want to add raytracing, you probably have to change the lighting from sector-based to source-based. That will inevitably change the vibe of some parts of the game.