The problem with this method is, that you have a board in front of you, which could also activate your QR (everything can happen!).
Or if you crash you will fall onto the board, which is a bad idea.
There are two solutions depending on your level:
1. confident with one hand steering:
- grab the board on the handle or strap if no handle is available
- either while you still ride or stop and get going again (harder to start with one hand only)
- while doing it during you ride, push the board first a bit forward so it gets some speed and you don't hurt your hand, before you grab it tight and lift it off the water
- if you are not so strong to lift the whole board during your ride, grab the front strap and let the rest of the board slide on the water while you ride
2. not confident to ride one handed
- simple sit on the second board!
- approach it slowly, grab the strap and get it to move forward and sit on the board
- you only need to take one hand shortly off the bar