Discussed on the GTNH discord last night; recap of the ideas:

1. Make the IC2 fluid/solid canner uncraftable. The only two recipes that aren't present elsewhere are its biomass and hot spring water recipes.
2. Add biomass recipe to GT fluid canner, or mixer if not possible.
3. Hotspring water doesn't even properly exist as a fluid, and doesn't seem to have any use. I don't think you'd need to add a recipe for it anywhere else.
4. Remove RTG? Mixed opinions here. It has a different use than the GT++ one, being a source of low-output and completely maintenance-free infinite power. Personally I don't support removing it although some people do.
5. Add a way to fill the biogas jetpack in the fluid canner.

I'd really prefer to leave the IC2 RTG alone. It may be infinite, maintenance free power, but it caps out at LV and is expensive to make. I rely on them heavily throughout my base for things that take very small amounts of power that would be tedious to hook up, like powering fluid regulators or crop harvesters. With how far along you have to be to make them, their cost, and their minimal EU output, it isn't exactly game-breaking.

Per our conversation on the GTNH discord:

If you could also remove the recipes being generated for certain ic2 machines automatically, such as the thermal centrifuge, blast furnace, and fluid canning machine. Those three come to mind immediately, but there might be more too.

Thanks!

just noticed the ic2 metal former has some lingering recipes as well,

also appears the regular ic2 canning machine has some lingering recipes.