Same here in Canada. The solution is that the machines accept a Canadian quarter to run the press, but an American penny to be pressed. No Canadian currency is harmed!
Only with intent to defraud is it a crime in America to deface US currency. Shaving a bit of the copper off every penny you touch, to melt down and profit from? Crime. Scribbling off the 1 on a $10 bill and scribbling on a 2? Crime. Cutting up pennies to show off the unmatched strength of your shitty kitchen shears? Perfectly legal.