The upgrade works with a caveat or two. On the Veyon Master machine, it lost all of the location and PC data. Having a .csv file on hand with that info made it almost painless to get them back. The "almost" is due to misinformation in the Veyon-Cli help information:
veyon-cli.exe networkobjects help import
show this as one of the examples:
* Import simple CSV file to a single room:
networkobjects import computers.csv location "Room 01" format "%name%;%host%;%mac%"
The above is exactly what I needed to do but it gave an error saying it failed to parse line 1. With no additional info available, I presumed something was wrong with my file... "Does it need a header row?", "Are certain keywords needed in a header row?", and other questions like that came up. After a few experiments, none successful, I noticed the ";"s in the format section of the sample line - changing those to to ","s fixed the problem:
networkobjects import computers.csv location "Room 01" format "%name%,%host%,%mac%"
And for those wondering, a header row in the import file is seen as data, so a new PC is created using the info it contains.
In the old config, I was using keys for authentication. The old keys still work, although I had to configure the Master and Clients to use key file authentication, as they both defaulted to logon auth. As I recall using the old keys may not have been possible back in the 4.1 days, which is what prompted my question here in the first place. It seems that if I'm remembering correctly, that has been addressed and fixed.
So the short answer to my question is "Yes". I hope this helps some else down the road...
~bd