I used to also bounce the bike off into first gear but stopped when someone told me that it was not healthy for the transmission. I started doing this after once running beside the K in a parking lot before I could stop it.It's easier to put it up on the center stand than to take it off IMHO. I always make sure the side stand is down and standing on the left side of the bike with it in first gear I rock it forward and "bounce" it off the center stand. Being in gear stops its forward motion and I preload it to the left so it winds up on the side stand.
So tell me, is there potential transmission damage to be done bouncing the bike off the centre stand with it in first gear?