Right now in the Transito UX you can 'remove' a feed which disables it from routing; however under the hood it doesn't actually remove the data from the database.
This was implemented so that the data is 'cached' and re-adding the same feed wouldn't trigger a reload of the same data. This is a helpful feature (which possibly should stay the same?). However..
There's a difference between:
Right now the UX let's you (1) enable and (2) load a feed. Both (1) and (2) in a single operation with 'Add' of the feed. But once you 'remove' the feed, it's not truly 'unloaded' (e.g. removed from the DB).
(If this functionality stays the same); We should implement some way to 'purge' the data from the SQLite database itself. The more data there is in the DB unrelated to feeds enabled, the more costly all DB operations are as the indexes need to be maintained (thus making subsequent load operations slower etc.)