I am using Drupal 8.
I have subthemed the Seven theme so we can add some minor customisation to the admin theme.
The new theme however is getting all the active theme's blocks thrown into - seemingly - random blocks inside its regions.
I want to create a subtheme which initially is identical to seven and can be activated across several sites with predictable block placement.
I don't want users to be put in a position were they have to go through and manually move/disable blocks after turning on the new admin theme. This is especially true given the clunky nature of adjusting block placement on the admin theme; every time you disable/delete a block and save the change it takes you back to the ACTIVE theme block page rather than the admin one...
Is there a way to do this?