As far as I can tell, this mod is currently missing support for method=overlay. I am currently using this texture pack, which is supposed to have overlay textures like this, but I cannot get them to work on CTMF.

That texture pack is meant for Optifine CTM, which this mod doesn't support. Use Connected Block Textures for Optifine CTM resource packs instead. If you want to know more about the different CTM formats, check this mod's CurseForge page.

Ah ok. Thank you for the info.