I've seen manufactured products that are roughly equivalent to this, but with a single long box plus mounting flanges for standard 19" rack panels. But are those products so much more expensive, or so hard to find, that people would resort to making their own line this? One I saw had 10 duplex receptacles and a cord with a strain relief and molded plug. But it was priced well over twice what I could make on my own with the above bracket.
Maybe an empty long box would be the better choice over 4 individual boxes that end up with single wires going through unprotected holes in DIY projects. Now we just need to get someone to make such a box and market it. It can either be an open front that comes with a full width faceplate. I'd suggest it be made with the "decora" style rectangular holes to be more flexible in the variety of devices that could be installed (including GFCI and switches). Or the box could be made with the face integrated and a big solid cover on the back that can be removed.
That wouldn't guarantee people would do it right. But it would make it easier for people on the edge to end up with something closer to right.
