I have a client that uses DPM for all of their database servers, including one using AlwaysOn Availability Groups, and they do full and log backups. I have been told they have tested the restores and it meets their business requirements. I was never given access to their setup to see what all it can do and how.

I would suggest you simply test it in a QA or development environment. The full backups act just like NetBackup or VMWare products that do a similar snapshot backup. They are meant to only take seconds but the I/O activity is frozen and then resumed. I never see issues on the application side, or have not been told there is at least. They run SharePoint on a good many of their servers and it may play nice with this type of setup more than other apps might, just something to test.

As a side note, the frozen and resumed I/O activity is logged for each database in the error log of the instance. So a server that has a high number of databases, and how often you perform this process, can make the log fill up rather quickly.