Faster MySQL Startup with Many Tables (1M+)

I have been scratching my head about MySQL startup for some time. There is much to say about this, and many other posts will probably follow. For now, it is enough to know that with many tables (millions) the startup of MySQL 8.0+ (including 8.0, 8.4 and 9.0) is suboptimal (to say the least). With very little changes, I was able to speed it up, from 2:39 to 1:09 (1 minute and 9