The sheer treasury withdrawal of pennies will force retail operations to start getting equipment programmed to round up to a nickle any figure ending at 3 or 4 cents, and truncate down to 0 any figure that ends in 1 or 2 cents. At the end of the day no money will be lost.
With the way the federal reserve’s actions gradually debase our currency, the same sort of adjustments will have to be made when it becomes more costly to mint a nickle than a nickle is worth; and down the road further with the dime, then the quarter, then the fifty cent piece, till eventually only paper money.
It costs 14 cents to make a nickel right now...some years (like last year) the losses in making nickels exceeds pennies:
https://www.jmbullion.com/investing-guide/numismatics/cost-of-producing-a-nickel/
Inflation/dollar debasement is relentless.
I suspect they'll be rounding down.
"I can hold up this line all day. You owe me 4 cents."