Block users to create specific branch pattern while allowing to merge prs

[systematicguy]

I would like to prevent users from creating a specific/* branch pattern, also disabling direct edits (only allowing pull-requests).

So according to https://confluence.atlassian.com/bitbucketserver050/using-branch-permissions-913474668.html:

• Prevent all changes - prevents pushes to the specified branch(es) and restricts creating new branches matching the specified branch(es) or pattern.

I can prevent creating a specific/* branch, but it seems it will also block pull-requests from getting merged, claiming You have insufficient permissions to update 'specific/stuff'

Any idea how to solve this? I am also interested in solving this via server hooks, if there are any options to do them. Although I need to make sure there is no way (not via git push, not via jira create branch) to create a specific/* branch, only allowed to some technical automation users.