You are allowed to remain in the museums after a tour ends. How practical it will be to revisit areas previously bypassed or rushed through is a different question. I did what you're asking about in March 2023 (though not on a tour) and it was manageable. But that was in March, two years ago, and not during a Holy Year. If you haven't been to the Louvre, Versailles, the British Museum, or one of the Gaudi sites in Barcelona recently, you will be flabbergasted at how packed the Vatican Museums are.
Because it is more difficult to walk against the general traffic flow, I think you'd be better off not taking a tour so you can move at your own pace and not have to retrace your steps. Note that the Pinacoteca is easy to bypass accidentally. If you want to see it, take a good look at the map you'll be given at entry and find it on your way in, rather than having to backtrack later.
I believe Rick has an audio guide for the Vatican Museums. You'll probably need decent earphones to hear it under the crowded conditions you'll be dealing with.