As you know, I'm one of the people who attached a piece of 1" X 1" square steel tubing to my G5's sidestand.
Thinking about this topic I looked at my sidestand extension and the centerstand with both of them in the "up" position.
I know we both have G5's but there must be some differences between yours and my 2011. My addition has a good 3 inch clearance between the square tubing and the centerstand footpeg. Strange!
I guess that's what happens when we get "hand built" motorcycles.
As for your additions, I'm glad their working but I fear the JB Weld is going to snap off the first time you forget to put up your sidestand and ride off.
It won't "touch down" until you make your first left hand turn and even then it probably won't cause you to loose control of the bike. You will just hear a grinding noise.
The impact with the pavement will do its best to break the epoxy bond and knock off your extensions though.
A washer that fits inside the pipe coupling but won't go thru its small diameter along with a bolt and a nut going thru a hole in the factory sidestand would make a strong assembly that won't break when it hits the ground.
Use a "fender washer" with the smallest bolt hole you can find for this.
The small bolt hole thru the foot of the sidestand won't weaken it too much and the large size of the fender washer will keep it from going thru the inside of the pipe coupling.