Andrew D. answered 09/03/21
Experienced and Plainspoken Teacher with PhD for Film Studies Tutoring
Hi,
While I haven't researched this and am offering an educated guess, I think your sense that the appearance of a long, uninterrupted take was created in post-production is almost certainly correct. After all, this is what director Sam Mendes did in his 2019 movie, 1917. As you may recall, that film appears to consist of, essentially, one continuous very long take, which we all know is impossible, a notion confirmed by the publicity and behind-the-scenes featurettes produced to promote the film.
I hope this answer is at least a bit useful.