Yes, it would be possible to hook into the acf/update_value filter and update or remove connections based on the $value.
This would be a very good solution, however, will require some complex coding which will be up to you.
As to your previous statement regarding post ID / object:
The relationship field will always save the ID’s, never any information about the actual $post. No change will be made to the DB by this option, only the returned value via get_field.
Basically, having the relationship field within the repeater prevents querying from being possible. If the relationship field is on the root level, then yes, you can easily query backwards and forwards from artists to events (there is a tutorial for this on the docs page).
I use p2p in my advanced websites and also, so does bbPress – the wordpress forum plugin!
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