Anti freeze smell in passenger compartment
I figure must be heater core but no wet carpet on passenger floorboard like I've experienced before
A small leak can result in the smell but not the puddles. When the engine is good and warm, after being driven for a period of time, I would bet that were you to touch the bottom of the air box under the dash, it would be quite hot to the touch.
get up in there and tighten the breeze clamps or install screw clamps if you cannot trust the factory wire clamps. If it leaks most likely from the connections-