The basic mod should work with FCOM or other overhauls fine since it only adds new spawn points and doesn't change existing leveled lists. I tested the first alpha a while ago and the amount of new creatures is really awesome. You constantly see creatures you've never seen before. And with new I mean really new, not just 200 recolors of the same mesh/texture like in some other mods.
There are still some small bugs and inconsistencies though, but I don't think there is anything that would completely break immersion or even something that would break the game. At least I didn't find anything like that.
It is unlikely that the mod will ever be 100% complete and unfortunately it's not a resource either, so it's a good idea to get what is available now and give it a try.
There is an OOO patch for WAC that is probably as beta (or alpha) as the rest of WAC (or because of WAC) on page 99 of the comments thread for WAC on that forum by C. Nail DeMencha. Others have reported using it with success. Uncertain about full FCOM, but having tried a relatively new character with WAC I can say that WAC makes the world very busy and dangerous place as it is focused on unleveled encounters. Combined with FCOM you would be encountering something every 20 feet.
I'm more interested in a WAC/TIE combination as they both are unleveled approaches and await CorePC's ne TIE4Mods to try and combine them.
Well that is interesting indeed, and thanks for pointing it out. I think if I can get my install stabilized I'm going to remove everything with extra spawns aside from the core FCOM (More Wildlife, etc.), pop WAC in and see how she goes. I like the idea of making the world even more dangerous.
I've never tried TIE, but I keep reading about it and it sounds pretty damn cool. I especially like the idea that you will run into unleveled creatures; sometimes the best strategy is knowing when to RUUUUUUUN!