I don’t know who would type in 30,000 notes. That’s a lot of typing. Maybe on a touchscreen keyboard, or in an app limited to that; it would behoove the OP to

I don’t know who would type in 30,000 notes. That’s a lot of typing. Maybe on a touchscreen keyboard, or in an app limited to that; it would behoove the OP to consider cross-platform possibilities and very long timeframes, or even look to use cases in similar systems. In org-mode (which I've got on my phone and desktop), I've got tens of thousands of lines, and could easily see keeping 30k notes. Granted, it's different, there's more than purely human entered data, but as the OP sagely observes, there may be automated systems inputting to Vesper someday.