So I've used the latest RC (3.16.RC) for Minecraft 1.7.10 with Forge 1208 together with TwilightForest (version 2.3.2) and naturally, there are BiomeID conflicts.
I've tried to change the config of EXBL to circumvent the ID conflicts by giving the conflicting IDs a new value (below 128), but every time I tried to load a world (no, not directly after startup), the config gets reset to the old values and TF gives me a "conflicting BiomeIDs" warning, thus forcing me to change the IDs in the TF config.

Can you have a look into that? Thanks :)

Yes, this is the same issue that was reported on IRC and the thread and Shecky is checking into what is causing this.

Alright, thanks!
Good to know this will be adressed :)

Per @JLBShecky this has been resolved.