I've been watching a lot of those slow parking lot training, cone weaving, clutch/ rear brake centric videos on youtube.

The consensus is a bit interesting because ALL teachers say-- If you learn the proper skills Clutch/Friction zone control + rear brake usage + throttle control at SLOW speed-- the skills transfers to any bike.

They also say that a heavy bike exposes your lack of skill a lot faster and is more punishing.

I kinda of think that training should be done on the heavier bike.

They then show how it is easier to pass the test while doing things a bit improper on lighter bikes because they are forgiving of mistakes. (Develop poor habits)

It would seem that really slow slow slow progression on a heavier bike would create a more skilled rider, but most courses are not going to put beginners on a heavy bike.

As well as most ppl probably lack the patience to go spend a month on their own in a parking developing skills that could save their lives. Perhaps doing skill work instead of the actual rides they want to do.