This is a bit more of a silly question, but I am genuinely curious.
On the dev stream, the stack size visually shows it going up to “999”, but it can (and will) go higher then that if you add more items to it, it just won’t show higher then that visually. However, I am curious what the “true” upper limit of this is, from it either being a “flat” limit (like 1,000,000 items) or an integer limit (like the 16 bit day count limit of 65535). It probably won’t matter in 99% of cases, but I’m always curious when it comes to things like this!