Hi,
Prep: Ideally the floors have had all the old finish scraped or sanded off, to a new bare surface. Shellac sticks to anything, but if applied over "unknown" stuff, like old oil finish, wax, etc, the drying times of the last coats will suffer; if you topcoat an existing shellac finish, one which has been waxed as in olden times, you will essentially be applying waxed shellac, with all of the pitfalls. It has to be really wax-free for this to work best.
I have easily applied four coats in a day in one room. The first two coats can go on immediately, since the first one dries almost on contact. As the wood gets more sealed, the drying time grows a bit. Sand lightly any nubs before the third coat. If you are applying on a good clean floor, and not picking up "trash" from the crevices or baseboard joint, one sanding between 2 & 3 is all that's needed for a good smooth finish. If you do notice a lot of particles/junk/"nerds" in the last coat, you'll have to sand again, after it has dried really thoroughly, then vacuum and coat again. You don not have to tack rag shellac, because any shellac dust will just re-dissolve into the next coat (unlike varnish, where its own dust is a contaminant) On a good drying day, I'd allow the third coat to dry at least an hour before going in (with stocking feet) to apply the fourth. The test: if your thumb, pressed to the surface as hard as you can, leaves a thumbprint. (if your thumb leaves a footprint, you have other issues)
I'd let the fourth coat dry overnight, then do a fifth (if desired) the next morning, and the sixth the next evening.
It's super easy to touch up, because shellac never changes color as oil varnishes may, it sticks to itself without any prep, and can be removed with its own solvent (alcohol).
When the alcohol has evaporated, there is zero smell, and the resin itself is non-toxic; it's actually used on foods, like M&M's etc. to preserve the surfaces. I think it's ideal for bedrooms or wherever a non-voc finish is required.
If you ever apply it over a stain, just let the stain cure fully before coating it. For oil stain that could be as long as a week, perhaps longer in cold weather. And if applied over an oil stain, the drying time between each coat, even the first/second, will be longer, so do the thumbprint test to judge if it's dry
Casey

That is awesome, Casey. Thanks so much for your detailed reply. I'm going to see if I can find this stuff locally, sounds just right.