Scheduled reminders silently skipped for contacts with a non-permissioned relationship associated with ANY inherited membership type

This bug affects a specific edge case where contact A has:

• 2 inherited memberships with different 'owner' contacts (B and C)
• Contact A has permissioned relationship with B but NOT with C
• Both memberships have properties such that a reminder is triggered for both in the same execution of Send Scheduled Reminders job

The current code structure uses a global {$notInClause} for the job which excludes non-permissioned inherited membership contacts from getting a reminder. This would need to be changed so that we have separate excluded 'slave contact' lists for each owner_membership instance.

— Original description —
I'm not sure if this is my blocker so will hold this & flesh it out as I figure it out but it seems the code for adding a permissionedRelationships where clause removes contacts from the scheduled reminder based on them having a non-permissioned relationship for ANY inherited membership - which means they can't get a reminder for a different (unrelated) relationship either.

static function permissionedRelationships($field) {
$query = '
SELECT cm.id AS owner_id, cm.contact_id AS owner_contact, m.id AS slave_id, m.contact_id AS slave_contact, cmt.relationship_type_id AS relation_type, rel.contact_id_a, rel.contact_id_b, rel.is_permission_a_b, rel.is_permission_b_a
FROM civicrm_membership m
LEFT JOIN civicrm_membership cm ON cm.id = m.owner_membership_id
LEFT JOIN civicrm_membership_type cmt ON cmt.id = m.membership_type_id
LEFT JOIN civicrm_relationship rel ON ( ( rel.contact_id_a = m.contact_id AND rel.contact_id_b = cm.contact_id AND rel.relationship_type_id = cmt.relationship_type_id )
OR ( rel.contact_id_a = cm.contact_id AND rel.contact_id_b = m.contact_id AND rel.relationship_type_id = cmt.relationship_type_id ) )
WHERE m.owner_membership_id IS NOT NULL AND
( rel.is_permission_a_b = 0 OR rel.is_permission_b_a = 0)