I find that jump mounting a 36" using the brake is very useful. With the brake locked I can firmly hold the seat handle with both hands and pull/push myself up with my arms. A jump mount on the 36" is quite easy with the brake holding the wheel fixed.
For new riders, shorter riders or really old riders like me it may be something to try. It seems to be very easy to learn, I just went for it and was successful with no real learning curve. The key is just to go for it and keep an eye on the pedals till the feet are planted. It also does not really matter what foot is forward or back.

Individual steps at: https://pbase.com/jimthode/image/168591638