Assuming I can reuse the code as much as possible, I plan to cross-develop to both Fabric and Quilt while it's feasible. If one of them becomes a burden to update, I will decide on which one to keep.

Main concern: config API

Currently works on Quilt 0.16.0-beta.8 without any changes (including Mod Menu, Cloth Config), therefore marking it as supported on Modrinth.
Edit: and now CurseForge as well.

Will remain marked as Quilt-compatible for the foreseeable future, until/unless Quilt stops Fabric compat. Will not test the mod on Quilt though, support will be provided as-is.