This appears to be the current process - can this be made leaner?
Non-admins create new workspaces
Admin identifies workspaces which don't have the correct custom layout
Admin manually adds the correct custom layout (I didn't find a way to bulk edit this section)
Non-admins need to go back to complete the 'new' fields
Possible solutions:
Allow non-admins to change settings when creating the new space
Or, for all workspace types which non-admins are able to add, allow default custom layouts to reduce the amount of re-work
Workaround at this time appears to be to add non-required custom fields to parent lines, and enable inheritance so these populate at lower levels - but does this not defeat the value of custom layouts?