I am using my custom list of bridges. When starting whonix gateway I see connections to all of them at once, I guess the availability check is done, then tor connects to a random bridge. I think this approach is less secure than just randomly selecting a bridge and connecting to it, without pre-testing of all, and then select another if previous is unreachable. Is there a way to change this behavior?
I don’t think it matters much if a connection was checked for or not. If it was done one by one it could take to much time to find a bridge to connect to. Regardless, I’m not sure how to do want your asking.
Does Whonix Modify Tor? See: