I remember trying to play a FFT+ hack in Mednafen. It wouldn't work. Is it true that FFHacktics Hacks only work in ePSXe? What about PCSXr?
ePSXe is pretty out dated.
FFT:Complete should work on any emulator as I tested it on console and it worked... however, I cannot guarantee the same for every other mod, in fact it's highly unlikely you'll be able to play most on pcsx-r since it seems to emulate the closest there can be to the real console compared to other emulators.
Some ASM hacks people uses, override some functions' limits a real console couldn't handle, thus making them playable on some emulators, and not on others or console. We are aiming to make Journey of the Five playable on console (not possible at the moment), but sadly I can't speak for the other mods.
Personally I use pSX, which emulates closer to the real thing than epsxe (still not quite), and requires no plugins. I hope you'll find a favourable solution that works for you.
All hacks on FFHacktics should work on epsxe and pSX.
I had exactly one problem on a very specific SVN of pcsx-r with the demo of Journey of the Five. Otherwise, the current SVN is my emulator of choice and gives me no problems.
But yes, pSX is very heavily relied upon, and all hacks should work there unquestionably.
I advocate -not- using ePSXe because 1.7 requires very specific settings to work without flaw, and 1.8 eats my memory cards quite often.