Since you won´t get any answer in here the best way would be that you simple open a support request. I did the same in June because I had questions about how to configure SSL and SSH regarding supported ciphers, MACs and so on. Actually for the 1910 series but since the 1920 is the successor and they managed not to change any settings if I take a look at the manual and CLI references ... also the 1950 still lacks a lot of configuration options.
Sadly my request was closed very quickly since my devices had no warranty anymore but thats not a question about one device it affects basically every single one. They just said they will hand it over to someone else and of course nothing happened.
If you open a new request you could reference to my request which has the case number 4651763275. I had requested a few more configuration changes based on results of a vulnerability scan.
Hopefully you have more luck.