To preface this, I want to say that this isn't so much a suggestion as a concept.
As someone who primarily uses Botania to help with automating other mods and for a couple of niche cases, I was thinking of a multiblock structure using an anvil, mana pool, managlass, and some manasteel blocks to make a kind of "magic anvil", which would repair items (not just tools) placed inside with mana. This would even have some functionality in regular Botania, allowing you to build a multiblock rather than getting mending on things like Elytra or Tridents. Just a very rough concept, that could probably be improved.