This is a very interesting discussion. I especially like the mathematical explanation by @cjdoris considering it as group action. For me the main concern seems to be that the group action is just denoted by an integer. For instance, in the example
Date(2022, 3, 16) + Day(1)
it is clear that Day(1) denotes a time interval/shift. In this interpretation
'a' + 1
should be understood and maybe explicitly written as
'a' + NextCharacterInTermsOfUnicodeCodepoints(1)
being open to suggestions for any other shorter, yet descriptive type 