Thank you for your work! My impression is that my internet is faster with 2.14.5, but this may be subjective.
Is tls-crypt enabled by default? I did not find anything in the settings.
What does "Enable latency tests" mean, and is it security relevant (traffic outside the tunnel or something like that)?
1 and 2 are tls-auth, 3 and 4 are tls-crypt.
The reason for having two of each is in case one is blocked by .... ISP or something.
If you resolve a server name, for example, "nslookup leo.airvpn.org", it'll resolve to its #1 IP.
I don't see a 3/4 in the protocols list you mention. 1/2 are just alternative IP's (entries I guess?) in case (as you say) one is blocked.