Current upgrade process for isolated environments feels underwhelming and it is a downgrade from applying patches through single, easily transferable packages.
Basically, if you want to perform updates/upgrades, you need to base on couple of community solutions:
1) You need to build a custom Veeam Update Repository Mirror Server (e.g. for Linux https://community.veeam.com/blogs-and-p ... rver-12216)
2) You need to create a custom script to pull data off https://repository.veeam.com/vsa/ (or modify the one in https://community.veeam.com/blogs-and-p ... 327&fid=57 - but this script will break file names with "+", do not use it unmodified). Note you basically need to move full repository every time - it was 40GB at first, then 50GB, 13.1 is actually 80GB+. In some environments moving this kind of data to the isolated environment is another hassle.
The problem is that now it takes much longer to patch, adds administrative overhead and it is partially unsupported and undocumented.
What I believe should be done by Veeam is to:
1) Add "Veeam Update Repository Mirror Server" feature into e.g. Enterprise Manager
2) Patches should be released two-ways: online via repository.veeam.com and offline through packages (probably two kinds: smaller delta releases and full releases) we could drag&drop via some kind of web interface on EM.
Hopefully this was already investigated and is on the roadmap