Don't we already have photons?

An addition of 'light' to TPT would require there to also be 'dark' areas, which necessitates a complete overhaul of every element. New colors, and such. Then, you need to make it so that only elements in the 'light' areas have light, and that ones closer have more so than others. This is just so... mindbogglingly unnecessary to have something that adds a purely aesthetic value to the game. No thanks.

It actually would be easy to code without implementing darkness or shadowing. It's still useless though, unless the light heated everything around it or something. Maybe it could behave like PHOT, causing all the reactions PHOT normally causes, within a radius set by TMP. I don't think that's what OP is asking for, though.

That doesn't make it easier to write. If it were to actually have light, dark and shadows it would be painfully difficult to write.