The first two are not contradictory, the first refers to communication between the client and server and the second to the browser's communication with a remote server. Maybe that wasn't clear from how I wrote it.
On further investigation, I think I was wrong on the second though; it might be that it's built into Chromedriver, not Selenium, which would explain why you didn't have the same issue with Firefox.
SSL between the client & Selenium server would be of benefit to keep any bad actor on the network from man-in-the-middle attacks on it. I'm not familiar with how I'd set up an ssh tunnel for that, I'm happy to believe it can be done, but it'd be a lot easier if it just supported HTTPS to begin with.
Apologies, I should have relaxed more of my verbiage. I was writing on my phone, and only about halfway through my post did it "click" what you meant.
HTTPS would be an odd choice, if only because I don't want to do any cert management for my selenium test runner. An encrypted channel makes some sense, but I'm not sure what the best mechanism for the shared secret would be. Ssh kind of gets you there, but is not as straight forward, as you ntoed.
Instead, I'd urge to keep the communication at localhost (or tunneled over SSH, at worst). Preferably with a locked down security model on the network so that you will see any traffic going off.
On further investigation, I think I was wrong on the second though; it might be that it's built into Chromedriver, not Selenium, which would explain why you didn't have the same issue with Firefox.
SSL between the client & Selenium server would be of benefit to keep any bad actor on the network from man-in-the-middle attacks on it. I'm not familiar with how I'd set up an ssh tunnel for that, I'm happy to believe it can be done, but it'd be a lot easier if it just supported HTTPS to begin with.