Hi Karol,
I've reproduced the problem.
I'll do a quick check to see if I can find a solution.
Edit: Problem found. Give me a minute to build a work-around.
Edit2: Fix is now on the AppStore as version 2.0.1. It now uses a 'Readonly' attribute if you want to have it as readonly.
Can you put the reference set selector in a (nested) dataview of entity B and refresh B?
Can you put the reference set selector in a (nested) dataview of entity B and refresh B?