Another thing for us to consider is what all features we might want to have, how well they can integrate with md, how well they can integrate with rst, and what will be the burden of trying to maintain parity between the two without an active rst activist.
Something that will help towards this is I recently started tracking the source format as an Enum rather than a bool (is markdown?).
https://github.com/cobalt-org/cobalt.rs/blob/master/src/frontmatter.rs#L270
Seems that there is at least one rst library though I do not know the quality of it https://github.com/flying-sheep/rust-rst
Another thing for us to consider is what all features we might want to have, how well they can integrate with md, how well they can integrate with rst, and what will be the burden of trying to maintain parity between the two without an active rst activist.