I think that everyone agrees that SGML conformance is very important,
but there are not many who are into it SGML to tangle with it in the
way you can.
(I know I should get sgmls up, but I haven;t even brought up half the
new browsers which have appeared, and I have to support a CERN user
community of real users and service providers. So free time is
nonexistent (having a little family may have something to do with
that too...). And there is HTTP2 which needs trial implementation as
well.
We get a student (Arthur Secret is coming back) in March which should
help.