I have to keep a stash of euros as I am over in Euroland quite abit. The larger the note the more face-value. Even for an able visioned person like myself it is nice to have that reinforcement that I am handing over the correct amount.
I don't mind having different sized bills in my clip.
As long as there is a PHASED-IN period where the new bills replace aging ones (they have a short half-life anyway) this is no big deal.
All the ani-counterfitting tech is immediately transferable.
They can have a contest for artsy bills and that could be fun and CHEAP.
Decades worth of Bureau of Engraving and Printing process, since 1929, has been built upon the fact that bills are 6.14 × 2.61 inches, and a full sheet of paper from Crane & Company is 20.88 x 24.56 inches. I think it'd be a much bigger deal than one might think at first.