More good stuff.

mstateglfr Like yourself, I was also thinking that putting a larger size of the same make/model of tire on the same rim would, indeed, give me a few extra mm but I'm learning that is not always the case.

To ​​​Wildwood 's point of N+1 I do also have a gravel bike that has some 32mm Continental 4 season slicks on some Zipp Course 30 rims and they measure 32.4mm. The combination of wheels, tire width and stiffness make a pronounced difference in feel; the gravel bike feels slow as hell getting up to speed but OTOH that extra air volume really works. Over some thousands of miles, I've broken a spoke but not had a pinch flat, or anything that felt like it almost was.

I'll report back in a month or two with news of whether or not the "28mm" 5000s has stretched at all.