Any chance this can be done without getDefaultInstance?
NuclearCraft-2.16f-1.12.2

Possibly - it will still require reflection though, which is always going to be slow. Unfortunately Mek does not include its gas capabilities in the API, so I have to get them through this slightly bizarre method.

Suppose I could ask if they could move it.

Talked to the Mek devs - I can use a feature of Forge capabilities that I had forgotten about to get the capability much more effectively. Will sort it out for the next build :)

Sorted :)