Dear society: you could just drop "sir" and "ma'am" and other gendered terms from your public service patter. Literally no one would know it wasn't there, and you'd save so much grief in the world.
"Thanks, have a good day!" has the same weight and impact as "Thanks, have a good day, sir!" No one would know. You could make this change right now, and save the sanity of so many people, trans and cis alike.