Entitlement seems only be for critical notifications (emergency alerts, alarms, overriding ringer silencers, etc).
Are you triggering the notify service directly from Damus Relay? If so I would work on "filtering" the notifies Relay-side.
In the same way that you would filter Relay-side that Bob only gets notifies on events for Bob's posts (and not Sally's).... A similar Relay-side filter should be able to filter out events from muted parties too.
Then use Apple Notify service under "Active" level, without need for entitlement.
https://m.primal.net/IMBJ.png