When creating worlds, I found that the nether biomes were not generating with the BYG and Promenade biomes included in actual generation. However, I found that the locations for them (in f3 and the /locate biome command) were working.

I feel this may have something to do with Amplified Nether, but I seem to remember using them both before

As seen above, the biome shown in f3 is a byg biome, but the game just generated a standard nether wastes biome.

Confirmed. BYG has an unlisted dependency on an older version of TerraBlender. Potion-Studios/BYG#1114 (comment)

Pushing change to 1.1.0 release. Sorry for the inconvenience until then. 79cc4cf

This also seems to be a slight issue in the end, with biomes not generating correctly (although I'm not sure what this biome is supposed to look like so I could be wrong)

I'll have to do some testing with this. I've never seen nether biomes have problem but I have noticed the end doesn't look quite right in the pack.