- Vital sustains (e.g. Disruption Shield): These are abilities that not only do you want cast whenever available, you *never* want to miss noticing that they were deactivated, because not noticing for a couple turns can mean a death.
New auto-use mode: "Always on" - Acts like "Auto-use when available", but also pops up a warning when the ability is disabled (even by the player). - Abilities that cost a turn, but should be cast regularly (e.g. Illuminate, Shielding): These are things that you want to cast whenever you have nothing better to do. "Auto-use when no enemies are visible" isn't suitable here, because you can waste a turn mid-combat if the enemies are invisible.
New auto-use mode: "Auto-use while automated" - The ability is case whenever it's off cooldown and the player would automatically wait (resting) or move (auto-explore, multi-tile click-to-move). - Resource-management abilities (e.g. any spells with Disruption Shield active): These are abilities that you want to cast to maintain a specific level of a resource.
New auto-use mode: "Maintain resource" - This has two follow-up options: Which resource, and what level. Levels could be specified as percentages, e.g. <10%, 10-20%, ..., >90%. This ability acts like "Auto-use while automated", but only if the resource is outside the target range and the ability's cost would move it closer. Only one level can be specified for any given resource (though multiple abilities could be used to reach it).
Resting should ignore the cooldown abilities with this mode set, and wait for the target resource level (or no way to reach it) instead of its standard preference for that resource.
Also, for the last one, it would be handy to be able to specify an auto-use target of "empty space", so that an archmage with disruption shield can automatically fire their beam attacks at adjacent squares to drain mana.