Discussion
FWIW, I believe the lightning network is already setting the standard 'millisat' (1/1000th sat) for when the need arises for smaller units. As the OP points out, changing a unit of account (even sats) would likely cause way more problems than it would purportedly solve.
If 1 Sat every equals $1, or $10, or even more, then it'll be so obviously needed that the network will be updated. IMO this is just a matter of time.
Absolutely agree. The protocol would be updated. Perhaps by scaling the base unit by 1000 so that there are 2.1 quintillion whole base units instead of 2.1 quadrillion. The protocol won't care what that base unit ends up being called by the ux software, though.
IMO, it would make a heck of a lot more sense for ux software to refer to that new base unit by a new name rather than try to redefine an already existing unit of account that currently represents 1/100,000,000 bitcoin.