I think it would be really useful to prioritize which actions your idols take. A lot of times I see idols doing auto-styling, when it would really be better for them to be recovering stamina at a doctor.
I want to rank activity priority like:
1. Recover stamina
2. Practice dance/singing
3. Styling
More precise control following this type of logic would be even better:
If under 50 physical stamina: Always recover physical stamina
If under 50 mental stamina: Always recover mental stamina
If over 50 stamina of either type: Practice dance/singing, if those are maxed then styling