Hey @timob,
I fully agree with all Aaron has said. Selectors have a severe impact on performance and will degrade the broker in different aspects like max queued messages, etc.
The better and recommended way is to filter on the topic hierarchy. The creation and administration of queues can be more or less automated via SEMP for example.
Uli and myself can support you and if you would like to discuss further, we can jump to a call at any time.
BR,
Alex