What exactly is "Automatic Code Signing for iOS" in 4.19?

I’ve asked this in both the answerhub and in the Unreal Engine 4.19 features thread, but no one has given me an answer. When I read that UE 4.19 was going to have Automatic Code Signing for iOS, I was excited for what it COULD mean, but I need to know a couple of specific things about this feature.

Question 1: Does this feature make it possible to use a FREE Apple dev account to launch a game to our iPhones for testing purposes?

Question 2: Does this feature work with Blueprint-only projects?

If the answer is yes to these questions, then I will finally take the plunge and upgrade to MacOS High Sierra to use UE 4.19 (I’ve been hesitant to do so for fear some of my Mac apps will no longer work properly, and that some files will be harder to find due to the new file system introduced in High Sierra. If anyone can put my mind at ease about this, that would be helpful too).

Thank you in advance for any helpful responses,

Tom H.