I'm now looking at guide.xslt and shorthand2xccdf.xslt to figure out how to handle the abject absence of namespace declarations where at least a half dozen namespaces should have been used.
Had libxslt been correct prior to 1.1.27, this likely would have caused some regard to explicit namespace declaration. As it is, to paraphrase Twain on Cooper, the rules of XML namespace usage have been flung down and danced upon.
Ha! Not an inaccurate description of what I've done. I'm certainly open to other solutions which respect the goal of minimizing overhead on the content creator.
It also is not at all immediately obvious how XCCDF 1.2 (part of SCAP 1.2) can be accommodated, but it will undoubtedly require explicit namespacing at or prior to shorthand2xccdf.xslt.
I was thinking of the conversion to XCCDF 1.2 as an ultimate (and optional) step. I think the OpenSCAP guys have a script/transform to do it, in a fully automated fashion. Given what XCCDF 1.2 requires for the formatting of the Rule and Group id attribute, it'll have to be done per-output, using the $(ID) in the Makefile...