What we really want and need is a tuple of integers, which stringifies to a dotted number and compares numerically

Well, I neither need nor want that wrt perl modules - but if others do, then so be it.
I'm quite happy just doing our $VERSION = "x.yz" where x, y and z are decimal digits.
I could just as happily extend that spec to our $VERSION = "X.Y" where both X and Y consist only of (one or more) decimal digits, and the length of the string being assigned to $VERSION is no greater than 16.

Cheers,
Rob