I don’t think I’ve begun thinking through all implications and I’m sure it opens a can of worms - not the least when dealing with scripts and plug-ins.
But I do not see it as a mapping of the comma to a period like you indicate with the text example.
Hitting the comma key would produce a comma; hitting a period key would produce a period. It’s just that a user could decide what symbol would be a separator.
I’ve taken the options box from Excel:
and changed it to what it could look like in Rhino:
