- **Cross-linking of forum posts and tickets**: the library can read and write them but they cannot yet be crosslinked. Related: add a context-specific flag which tells crosslinking to simply skip these, rather than fail.

- **Double-check crosslinking of other types** and make sure that we are not missing newly-added features.

- **Bring the configuration-related state up to date.** The infrastructure is there but the exact list of fossil-supported properties is lagging behind by several years.

- **Stash** support. First requires merge support.

- **Unversioned files** should be trivial to do.


# Security-relevant

But not otherwise SCM-relevant...

- **Port over `db_unprotect()` and `db_protect_pop()`** APIs, which allow a db to effectively be made read-only except for limited windows where specific sections of it needs to be writable. Related: `db.c:db_top_autorizer()`.