It would be nice quality of life to have different tabs in your equipment, being able to swap between different disciplines and have the gear+relic stored within the tabs, so that you don't have to keep the extra gear in your inventory if you'd like to swap disciplines. I would also recommend making this non-swappable in combat to avoid weird meta issues, but I think that is relatively obvious.
Example: Player is playing Demon Knight, but wants to swap to Infuser. Outside of combat, player opens equipment and changes to preset 2, which causes gear and relic to swap.