I led in a variety of roles at Ford over 23 years. My last job included, among many other things, all of the Truck and SUV wheel and tire machines and the associated processes. I'm unsure of other manufacturer's policies; but, Ford did not balance spares for the same two reasons that were used on anything that didn't affect safety, compliance, warranty, long term durability or measured customer satisfaction: Cost and weight. To balance a spare would require additional cost and weight. Many customers go through their entire ownership experience without using a spare, so, relatively few are ever affected. Factor in customer sensitivity to balance (even ability to mount their own spare) and the number of affected customers shrinks further.
In Kentucky Truck Plant where both SuperDuty's and Expedition/Navigators are produced, they have to mount, inflate, and balance a wheel/tire combo every 6 seconds. When I was in charge nearly 20 years ago we were running that plant about 112 hours a week, 49 weeks/year. 20 years ago, we could pull VIN specific data for years that listed serialized wheel, tire, weight, pressure, etc. of all assemblies for quality containment reasons. The completed wheel/tire assembly was all done with virtually no human contact. Think about that the next time you're sitting in Discount Tire watching them mount a new set of tires for your Expedition. It's a fun process to be involved with. People talk about high tech....that's high tech.
Probably more info than you wanted...
All that being said...I only drive them now. I engineered a spare wheel/tire combo (balanced) that stows and functions for my '12 GT500 because it came without a spare (!). I bought a right sized off-road suitable spare (mounted on stock spare wheel and balanced) for my '22 F150 FX4 to replace the temporary (virtually tread-less) spare that it came with (criminal). The '20 Expedition only needed balancing and flipping. The main reason for the orientation of the spare from the factory is a virtually imperceptible reduction in escape angle combined with increased visibility of the "hidden" spare, which styling did not like when the tire is secured face down on some vehicles.