Here is what I would recommend to do on the AT3 to have a reliable and long lasting structure:

1) Reinforce the rear main former with a small 5 mm plate that is glued and pressed by the wing tube bracket socket head screws ( you'd would have to remove the 4 of them before gluing the plate of course )



2) reinforce the main landing gear area and wing tube box/main spars.

3) put the main gear on flex plates.