Ok, I've made them compatible. Turned out not to be too bad! I mostly kept all of both mods, simply updating so that FE+ also uses this mod's titanium.
You should be able to add Titanium to an existing FE+ game (you'll have to explore really far to find the ore though). However, you won't be able to add FE+ to a Titanium game, or remove either if both are on. I may try to fix that at some point, but it's a little trickier.