We are planning to test SharePoint CU patching activity on one of our test server where trial version of SP2010/2013 is installed.
Can we do a CU patching on Trial version of SP2010 or 2013?
As a short answer Yes, you can.
The Cumulative update doesn't care about it was a
licensed.It cares about the SharePoint Edition:
So before installing a new CU. you should be aware of
As long as your trial period not expired, Yes you can apply patch on that farm. There is no such restriction for the trail version.
Patches only check the Install version of the SharePoint ( Foundation or Server) and don't care about the License type ( Trial or Standard or Enterprise).