Dunno. I tried looking at it but it doesn't have any public source code, so you'll have to take it to them.
Due to the nature of how the ReplayMod functions, it has to more or less manually add the recording player to the recording. So, if some mod modifies the recording player and does not do so by merely sending a packet to the server and letting the server modify the player, then the ReplayMod will have no chance to record it. There's nothing we can do about that, the ReplayMod only records packets coming from the server and if that's not enough for some mod, that mod would need to be changed.
alright thanks, i was just wondering if it was possible but since its not, i now know, it wasn't a bug on my side of things