Ronald, I use a similar device but found that kneeling gives a little lower center or gravity. Once my knees are on the bar my waist is above the cross beam. So, you might try shortening the ropes, that worked a little better for me.

None of these things is of help if you get separated from the Boat, whick is my biggest concern.

Yes Pete, y're quite right with the little lower center of gravity.

But I found out that searching the bar with my feet is easier in rough wave conditions. When I swing my leg over the center-line, my feets are already close to the bar.

Moreover my feet feel more stable on the bar then my knees and standing gives me a sort of mental boost in the tricky situation of the capseize.
When I arrive in the standing position, I know its done, I'm out of trouble.

Finally I was looking for a method which could also be used when I was hurt (maybe twisted something or even broke something). I hope that this trick will give me the best chances in bad unforeseen circumstances.