Thanks to everyone. I have added quite a bit of material.
The sutf is interesting: it is kind of the reverse of the STF approach which puts in PIs into test documents to say what the expected results of validation should be.
It seems to me that the current gaps in Schematron capabilities (as distinct from performance/bugs) are
* How to integrate into TDD better
-> SUTF? STFF?
* How to sequence phases
-> XProc? Allow one phase to select another phase on successful/unsuccessful completion?
* How to handle XSLT3 (Qery Language Binding)
-> allow let/@as and param/@as hints?
-> What to do about streaming
* Should there be some JSON story?
-> XSLT3 converts JSON to map, so should Schematron allow rule/@context to be a map?
Regards
