A command to edit configs directly would really open up gameplay possibilities (for modpacks, etc...) if users wanted to change configs when certain milestones were reached, events occurred, etc... Obviously some mods require a restart no matter what, but the infrastructure seems to already be here for reloads/reregisters.

If that's too much, a command to simply trigger the existing code to check for config changes and fire the required event for forge to recognize them would also accomplish this if combined with mods like Config Swapper or Simple Config (both allow for command based config edits, neither update forge that the configs have changes as consistently as Configured does).