How can we check which content SEP 12.1 clients are downloading from GUP?
You can find events regarding updates from the GUP by going to Monitors > Logs > Log type: System > Log content: Client activity > View log:
As shown in the screenshot, you can filter it by selecting appropriate event type (Client events) and Event source (SYLINK). You might then save the filter to do not have to configure it everytime.
You might click on Export at the top of the screen to get the results in CSV file, so you would then be able to edit it in Excel, to make a document that would fully match your needs.