Bound translateable element attributes

Working example here:
http://emberjs.jsbin.com/dopoz/2/edit

Using "data-bindtranslateattr-xxx" as to not confilct with regular bound attributes.
In that case, perhaps we just *always* assume bound. (We're already always assuming *reference*, not *literal*; it's just that the references aren't bound.) With that assumption, is it possible to rewrite this in terms of `registerBoundHelper` so we don't need so much duplicated boilerplate?