syslog - message based LB

We are trying to migrate our syslog to Azure and encountered an issue where IAAS based listeners have a 500 messages hard limit as far as syslog goes. I am trying to find a way to configure F5 LTM to load balance syslog traffic using message based LB ( or MRF? ) with 500 messages high watermark per pool. Has anyone tried this before ? I know there is diameter profile existing but i dont think i can apply it on syslog traffic.