Earlier last month I shared on how to configure the DPM 2012 R2 with Azure Recovery (Backup Vault).
Microsoft Azure recovery Services team has officially released the backup per protection group from 1.7TB limit and now to 54TB limit on 12th Aug 2015.
You need to have the Azure Recovery Services Agent 2.0.8715.0 or higher in order for the backup to exceed the limitation of 1.7TB.
The news release is here.
keynote : Azure limit, ASR, Azure Recovery Services, DPM, SCDPM, storage limit.backup limit