How to position a tag over an entire tree in a single pass

Nextcloud version (eg, 20.0.5): 26.0.4
Operating system and version (eg, Ubuntu 20.04): Debian 11
Apache or nginx version (eg, Apache 2.4.25): Nginx latest
PHP version (eg, 7.4): 8.1 FPM

I try to restrict access using Flow and automatic tagging on a relatively big tree.

Works fine with newly creted files but the existants ones need to inherit the restricted tag to protect the whole existing tree. So :
How to position a tag over an entire tree in a single pass ?

Is there an occ command to achieve this ? (Found nothing in the forum nor in the admin doc…)