Papal Visit plus Vatican Museum plus Jubilee doors - too much?

Then with the exit from the Sistine Chapel near the front of St.
Peter's...

I'm a little concerned that you know exactly where you'll be exiting the museums? The standard exit is essentially at same place as the main entrance on Viale Vaticano. It doesn't exit the Sistine or come in near the front of the basilica. There is another exit from the chapel directly into the basilica but it's only accessible to tour groups, and only a select number of those.

So I guess my question is if you booked a tour that allows you to exit into the church that way? Otherwise, you'll leave the museum and walk back along the walls to St Peter's Square pretty much the way you came. Or am I confused (entirely possible)?

To add: you might find some of the Holy Door experiences from recent visitors on this TripAdvisor page to be helpful?
https://www.tripadvisor.com/ShowTopic-g187791-i22-k14282072-o80-Holy_Year_Jubilee_2025-Rome_Lazio.html

What i'm a little skeptical about are some reports of entering the basilica through the Holy Doors without having registered. I'm wondering if that will change this spring when crowds become heavier, or they've just decided it was too much trouble.

Oh! The last time I went to the Vatican museum (with a Rick Steves tour), we exited to St Peter's Basilica, so I just though that was the exit for everyone...
And I could see the exit on the map in the Rick Steve's Rome book - so I just assumed it would be the same. But I suppose it is not an issue to have to walk back again; I understand it to be a 15 minute walk.

Do you have any insights to going through the doors?

I have read that there are long security lines to enter St. Peter's, but I am thinking that there is a separate line for the doors, for which one needs the reservation on the Jubilee App. Does anyone know?

The guards for that door used to be a little loosy-goosey about access to the passage from Sistine into basilica but now even the Vatican's own tours for the museums don't allow their customers to use it. You have to be on a museums+ basilica combo tour (the Vatican doesn't offer one) that includes that benefit. Again, take a look at the firsthand review (#83 and #84) in the TA link I'd provided regarding the Holy Doors. This comment:

"But you can't enter St. Peter's directly unless with a tour, so we had to exit the museum and walk back around to the square."

I've no firsthand experience with the Holy Doors but in addition to the one report I'd linked, here's another:
https://www.chiluxetravel.com/ultimate-guide-to-visiting-st-peters-basilica-during-the-vaticans-jubilee-year-in-2025-holy-doors-tips-and-must-knows/

Of interest in that blog piece:

"We actually had absolutely no idea what we were doing when we were there, and had no clue where to go, but there are gobs of volunteers in bright, fluorescent green jackets walking around to help. I simply showed them my app and QR code, and they let us through to the special line. No one scanned my code or anything, and we were an hour late for our “reservation,” but that didn’t seem to matter. I suspect it might start to matter when there are greater numbers of people in the spring and summer."