I'm again tinkering with Orbital Mining, and it is a pain in the A... urora Game.
I'm not listing all what is needed right now. Suffice to say that it is micro-management at the finest, without help from Events.
So here is my suggestion to make OM feasible (maybe at least some of it is doable):
1. Change Standing Order "Move to Asteroid Mineral Source" to "Mine at OM Mineral Source" and don't remove it when destination is reached (similar to Science Vessels).
2. Add Condition "Cargo Hold more than 90% full" and add Action "Unload Cargo at Colony (with Pop)".
3. Don't request to make all OM-Eligible bodies a colony.
3a. Let the civil mining companies check, if there is an Orbital Mining Module present before establishing a CMC.
or
3b. Let the Mining Module make the body a colony and delete the colony when all minerals are mined.
or
3c. Add a button to "System Generation and Display" with "Create all OM Colonies". And another one for "Delete empty OM Colonies".
That way you can nearly fully automate the OM, similar to the fully automated colonization.