Public boards under private workspaces are shareable to all with no permission

hi, we are using Enterprise
one of the basic ideas of Enterprise is to allow a few teams to work in parallel while allowing data security and preventing commercial data risks.
Monday recommends to do that using private workspaces and boards, where only the owners can add more users.
however - if we want full separation between workspaces, i can understand that on the workspace level - but on the board level… trusting each board owner to not invite anyone from a different team is a security risk, and trusting the human factor here is problematic.
so the request - there should be an admin level permission that restrict the option: either on the workspace level or on the board level.