I will admit that I have only the most surface level understanding of what the title to this post means. Garbled circuits seem cool though (in the same way that I think all cryptography is cool). They apparently make it easier to build more complicated contracts like SNARKs.
Anyhow, Glock (#1086220) was released by Alpen Labs last year, and this new research seems to be a piece that can be used with that to BitVM less monstrous.
Sidebar 1: There was also this discussion on the Bitcoin Dev's Mailing List that mentioned ZK proofs as an attack on Bitcoin (#1333295)
Sidebar 2:, I'm still confused whether efficiency in this context means takes up less room in a block or takes up less computation to do the verification. Something I apparently need to look in to.