Thanks for the reply.
I was aware it was possible but as this is a mod pack I thought I'd put forward the suggestion to the authors. It also means I don't have to make the same ID changes for each new version.
Pending permissions, it would be great if you could the following two mods. I believe they are quite well liked, up-to-date and add a lot of value to the game.
Twilight Forest
Extra BiomesXL