WowAce

This is more of a question of whether this is intended - are we able to customize indicators depending on theme? e.g. in raid, I want fewer icons than in m+.

In the indicators tab of each theme you can disable/enable indicators.

This can be configured too in the indicators "Load" tab, using the Theme load condition.

Ah I see, so indicators themselves don't have theme-specific settings, I'd just have to duplicate the indicators and then make the changes there, then save as new indicators with specific load settings?

yes