The full ramifications of the lodge space and its atemporality are often glossed over, I think. FWWM already demonstrated that using the lodge as a conduit, time can be entered at one point and influenced at another. It's not so much time travel, but that the lodge is exempt from the way that reality operates. I really love theories that lean into the direction of the lodge being a place of permanent consequence, and so the ending of S3 resonated with me immediately; the idea that once you enter, owing to the time qualities of the lodge, it's immediately the case that you have always, or already, entered. You entered there before you were born in reality, and so you are required, in reality, to eventually enter.
In an ordinary time travel schema, the past is subverted if a change is made by a future traveler; but the lodge space seems to do far more than over-write reality at a branching point, it seems to have fittingly abstract consequences.
So I personally have always viewed the birthing scene as something that shouldn't be taken in any chronological sense--it could even be a rebirthing scene. When the BOrB is shattered, it doesn't disintegrate--the shards float up and spectrally phase past the ceiling. Perhaps what we see here is an ending leading to a beginning, or more like the beginning of BOB is always the same. When we see the BOrB emerge from the Experiment, it has just gone through its destruction.
I was elated when Frost liked a theory via Twitter the other day where someone was postulating at this angle, saying that the Laura orb creation is actually Carrie, and so the workings of the Fireman in this scene aren't a direct chronological response to what was happening around the bomb detonation, but was a reaction that begins to take form all the way forward in Part 17, when Laura is removed from Cooper's hands.