this was something I had meant to do a while ago but abandoned because I couldn’t come up with a way for it to reliably work across all the different kinds of shape (there are a lot of different face shapes with different edges), but recently I improved the code I use to find each face’s centroid for label placement using edges and I think it might be possible to adapt it to generate face frames... this is definitely getting bumped up my to-do list again, though it might not be a priority for the next version sorry.
in the mean-time, I know it’s a bit of a fuss, but you can make face images which include both the face display and the frame artwork.