It would be nice if there was support for chisel, at least to the point of only having to set one EMC value per item for chisel only blocks. For example unlimited chisel works adds a lot of various chisel variants of blocks, and it is a pain having to set the EMC value of each and every one.

Chiel uses oredict, so setting emc to an oredict is possible, I don' know about unlimited chisel works though.

I don't think chisel purely uses oredict given it is also possible to add custom ones using ModTweaker https://docs.blamejared.com/en/#Mods/Modtweaker/Chisel/Carving/ So my guess is they have some system to keep track of the conversions; you can probably look at ModTweaker to see how chisel keeps track of them.

Also I vaguely recall at some point trying to add chisel variants to the oredict and it not working properly for some reason.