It's a neat looking configuration, I'll give you that, but....
The top of the mount is hanging way out there in space with no support in the direction the brake will apply the most force. Also, there's just not enough metal in the dropout to make up for the missing support.
This is for a road/touring bike, right? At least it won't see an mtb level of stress and it will last longer that way.
I see where you are coming from. Personally I don't like the look of it hanging way out, these dropouts were kicking around and I felt they would work ok for touring, mtb mind you I would want something closer in. The design I must say however is 1/4 cromo with a flex compensating design. They should suck a bit up, and those DO tabs go nice and far in. Looking at it, a better remedy would had been to place the support on the seat stay a few inches fore. At 1.2mm on the stays ends though im not going to hold my breath, but good eye!
Airbust. The seat stays had some plugs made and where brass brazed in. Then heated up and hammered around a proper size pipe. Then put in to place by holding to test fit, back and forth until they snugged enough for the silver to have enough surface area to do it's job, followed by a bit of finishing and then brazed in place.