opinions on my DIY bag brackets

[BR3W CITY]

While I don't have the most favorable opinion of air-over-leaf, I'll keep it to your question.

If it were me, I'd throw a stitch of weld on all the sides where none was put. IMO 1.5" long stitches about the same apart would be my choice. There is nothing wrong with welding on the other side of where the first welds are, just keep your heat under control, since everything is already squared up.

I don't know about the rest of your setup, just make sure that at FULL compression (under some weight) the girth of your bag doesn't rub or touch the walls of the bracket. I had cups that came close and eventually rubbed, causing a near blowout.