With the hide from frontend, that hides full metabox groups and so you need to have it [block A - for x user], [block B - for y user], [block C - for all users]
Instead I have it:
field 1 - for all
field 2 - for x user
field 3 - for y user
field 4 - for all
So it is embedded. There seems to be no conditional logic for user_role per field, so wanting to understand how can best achieve that. Unless I got it wrong with the Include Exclude.