Thank you for posting your question on the Mellanox Community.
Unfortunately, you cannot disable the capability on the adapter itself.
You can, however TM Offload is disabled by default or enable when you are using UCX.
- UCX_RC_TM_ENABLE=y -> h/w Tag Matching Offload enabled
For more information, please see the following link -> https://hpcadvisorycouncil.atlassian.net/wiki/spaces/HPCWORKS/pages/141230081/Understanding+Tag+Matching+Offload+on+ConnectX-5+Adapters
Thanks and regards,
~Mellanox Technical Support