We have several message sizes being pushed to UM Topics (Small, Medium, Large). Small and medium process OK, but the JMS Topics processing for large message slows down the Integration Server and pushes the IS to a hung state. Could moving to UM Queues from UM Topic resolve the large 5-10MB message processing issues? Please advise.

Hi Aamir,

UM can easily deal also with large messages as long as you configure your "MaxBufferSize" properly. Default is 20MB.
https://www.ibm.com/docs/en/webmethods-integration/wm-universal-messaging/11.1.0?topic=administration-realm-configuration
The question is about your problem with the "hung state" this is very unusual.  It might help to set the UM Client logger to TRACE as
well as check the UM Logs to see what is blocking.  Assuming you are active customers providing the logs as part of an support case
raised should help you quickly. 

How many subscribers do you have for this Topic? Are there any joins on the trigger on the subscription side? If yes, see if you can test without the joins...I have seen these joins cause performance issues in the past. You also might want to look in to the trigger service processing these events for any performance issues. There might be a hold up of threads on the subscription side on the IS.