BIP 177 is terrible.

1. It will happen again: Multiple BTC "stock splits" will be needed over time. We will go much smaller than 1 sat. We can either create a new name for each of them or constantly change what "1 Bitcoin" means by adding or removing zeros like fiat does. To make matters worse, because it is an Ok move to make, each county can decide to redenominate BTC for their people. This is a can of worms we do not want to open.

2. Stock splits force updating the past since what was 1 BTC last year is now 100,000,000 BTC. All accounting records related to BTC must change. Since a lot of systems are stuck in time, it is likely that we will need to add date-and-timezone-dependent rules to adjust units when doing reports over old systems. This is equivalent to the current "daylight saving" problem, where each country has multiple historical tables to adjust time when doing reports.

3. The International System of Units never changes the unit of account. Users are supposed to add a prefix (nano, pico, etc) as things get small or (tera, peta) when they get too big. Keeping things historically sane significantly reduces the work of engineers. I don't need to remind anyone of the multiple mega bugs these types of conversion issues have caused over the years.

1 BTC = 1 BTC.