I've uploaded the "BackplaneStandard" set of items to the HeroMachine 3 Alpha for your enjoyment. It includes new backpacks, wings, capes, and a few other tidbits. Here are three sample items from the new collection:
I'll be adding "BackplaneWings" and "BackplaneTails" sets in the next few days, that's what I'll be working on next. I think it's important to get those fleshed out.
As always, if you see any Backplane items you want but which aren't already in HM2.x or 3.0 Alpha, let me know in the comments.