And how would that be helpful? Even if the user, with very limited knowledge of the vpn server and its config or general knowledge about vpns, is even able to

And how would that be helpful? Even if the user, with very limited knowledge of the vpn server and its config or general knowledge about vpns, is even able to describe a bug appropriately very few bugs are unknown bugs. From my 10 year experience working with Cisco and similar products (including client vpn) I've only reported a handful of unknown bugs to vendors, so in almost all cases it's already been fixed and software needs to be upgraded, or it's a config issue, or some other issue that can be worked around by IT.