American paper currency has been printed using the intaglio process for at least the last 60 years (and probably for more than a century). I could see phasing in braille dots and larger, more boldly embossed numbers--which could be programmed into current electronic note readers. But changing the size of the notes? That's crazy! It would make millions of electronic note readers useless. That is a very bad idea.
Having said that, this whole decision is stupid. It belongs in the halls of Congress or the Bureau of Engraving, NOT in the hands of some looney-tune federal judge.
As I say in my original comment I agree that it's not a judge's job to do this. Also agreed that there may be other solutions besides size differences.
But I long ago noticed the federal government ordering private sector and municipalities to spend billions to comply with laws for disabled people passed by Congress while blithely ignoring the problems blind people have with money printed by the government.
One solution is to turn over the design of currency to the private sector (say Halliburton) which will prompt Congress to impose regulations requiring that the notes be "readable" by the blind.