Sending a message to all logged in resources (regardless of priority)?

I am wondering if it is possible to send message(s) to all logged in resources (for that user), regardless of priority.

I have enabled route.all-resources on my server, but although initial message will be sent to all resources, if one of the clients respond, consecutive messages (from/to same user) will be sent to the client that responded. After idling time of 30 minutes, any new message will be again sent to all resources.

Is there maybe a way to reduce that timeout somehow?

Thanks.