This photo should have been included in my post earlier today. It shows the 2” piece removed from the tip of the Cradle leg.
View attachment 5344596
I have performed the fix you suggested. That was very fast and easy. And as I had indicated, I come back to report about my observations.
Removing 2 inches of tube length on foot 2 indeed brings the arm C more horizontal, and as expected, this reduces the push of the back of the bass on arm B. Apparently, it seems that this would cure the problem I had mentioned (foot 1 slipping away from the bass on a very smooth hard floor).
Unfortunately, this creates another problem: Now, there is not enough support on the front side of the bass (foot 2 does not extend far enough to the front to provide a wide enough polygon of sustentation). Actually the is stable when placed on the cradle, but the safety margin to prevent a front crash is rather slim, and there is a risk of accident if someone knocks the bass or the cradle. When I perform the maneuver you call "the wagle" to check the proper placement of the bass on the cradle, the feet 1 and and 3 tend to lift themselves from the floor. This is really annoying.
Again, all this is very much dependent on the shape and size of the bass and extension of the endpin. But the geometry of the cradle is too akward to get a good feeling of whether or not the bass is safe.
I think that the various problems I have reported can be cured by performing some changes in the design of the cradle, but in the present version I wouldn't use it, nor recommend it to others.
Thank you again for taking the time to exchange with your customers on the forum.