All American Standard and Trane heat pumps have demand defrost.
Lennox uses demand defrost on their top end units, I'm not sure about their lower end units.
I think Carrier uses it on some units, I'm not sure though.
Rheem/Ruud use it on at least some of their units.
I have no idea what other brands are doing on their newer equipment.
If more government is the answer, then it's a really stupid question.
I retrofitted it myself using a YorkGuard IV controller from leftover part stock. Works great and rarely defrosts, only when needed, as advertised.
It was not a difficult retro, but having all of the parts and sensors available was a key part. I actually did it in the mid of the first winter season when I got tired of hearing it defrost every 90 minutes, and not seeing any frost.