I was wondering if anyone ever proposed extending the presidential dollars to include Carter, and found this: https://www.congress.gov/bill/119th-congress/senate-bill/633/text This, if it ever passed, would just indefinitely extend the presidential dollar series, covering any president not already honored, and their spouse, within 3 years after the time they died, rather than requiring a separate piece of legislation for every president. But last I checked it hadn't even been voted on in the Senate, it looks like. But it's possible it might be re-introduced (or another bill that does essentially the same thing might be) eventually. Anyway, just thought it was interesting. This might be old news though, and so far no action has been taken on it.
Coins are pork in the budget, paying artists fee's Etc. is expensive. I am hoping for more out of our politicians.