The details about falling assumes Earth level gravity too. That might be different enough to change the scale of things. When gravity is especially high you aren’t likely to evolve very tall creatures because vertical movement becomes punishingly expensive.
For massive size differences I would expect that to affect brain size and intelligence. Below a minimum size you’re not likely to get higher intelligence because the brain just isn’t complex enough.
There’s also interesting problems with heat. Larger bodies have less surface area to dissipate heat and so are more prone to overheating. Tiny bodies may lose heat to their environment too easily.
A 4D printer would need to know the time.