Will be trying out a few ideas tonight.
How about if I added an "_OR_" tag that when present would have SemiRandom look for a province with any of the included terrain flags? I think this is in line with what you were suggesting.
So:
Endo2_U_A_OR_N_L_S_WST_SWP_FST_.gan
Could only be placed once (Unique) in Normal, Large, or Small provinces which include the terrain type of Waste, Swamp, or Forest.
Need to get some coffee in me and then I will dig into the code and see what I can do.
