Keystone Cougar - Installing 2nd AC - Roof cut

Have a 2016 Keystone Cougar that was wired for the 2nd AC.

Last weekend, removed the vent and put up a 2nd AC, an Dometic Penguin II.

Fairly easy to do, but getting the old sealant off was a pain. And in some places, it just didn't come off (it was stretching the roof membrane, tearing some of it, ect).

Anyways, cleaned it up the best we could, got what we could off, noticed a tear in the roof that was about 1/2 outboard of where the roof opening was, maybe 4-5 inches long..

Well, the seal for the AC covered up the cut in the roof, so I decided to roll with it, install the AC and see how it looked.

Looks fine (IE the cut is under the AC seal as far as I can tell). Doesn't seem like it is leaking, at least nothing obvious, but I know where it would be leaking wouldn't necessarily be noticeable from the hole.

Anyways, second guessing myself now, thinking I should just pop it back off and put some 4" Eternabond tape (just found out about this stuff) basically on the outside of the AC hole in the roof, then mounting the AC back up.

I have read lots on people using Eternabond on the seals and what not on RV roofs with great success, but haven't seen much about using it under an AC.

One of the concerns I have doing it, is when the tape is overlapped, it will create not perfectly flat surface, and quite possible a way for water to flow between the tape and the AC seal.

Any opinions?

Anyone used the tape under an AC? Any issues?

Thanks for the help!