Hi Timothy, I'm quite exited and impressed to see this alternative to minted, thank you.
I haven't been able to test your patches to org, but I have tried engrave-faces.el. Here's a couple issues I've run into. 1. engrave-faces-generate-preset generates emacs colors such as `:foreground "grey70"` which are not supported by engrave-faces-latex-gen-preamble-line and co. 2. `minted` supports a `mathescape` option to render math content inside code. `fvextra` supports the same option, but maths characters are escaped by engrave-faces-latex-face-mapper. Regards, -- Sébastien Miquel
