Heart rate to watts/effort

It’d be good to know what heart rate/effort ranges should correspond to zones 1,2,3 etc. ie is zone 2 purely aerobic? For example MAF formula of 180-age (+/- 5 beats depending on recent history etc). When setting up a training plan it’s hard to know how hard/easy it should feel…

That’s going to vary a lot from one rider to another.

The ability to construct zwift workouts based on heart rate rather than power would be useful at times.

When I use Zwift I train all by heart rate. Watts is nice, but I don’t care how many. It’s all based on my hr.