Safari consistently fails to process XSLT when it includes an XPath with a namespace which is the first non‐default namespace declared in the root element, but only sometimes
the name or value of the namespace does not appear to matter; however, and for reasons i cannot seem to determine but presumably has to do with document structure somehow, it only manifests for certain namespaces which have only been used in the document in certain (specifics unknown) ways
it’s not whether it is the first non‐default namespace; in fact it is just that some namespaces must be declared before others (by some unknown‐to‐me standard) or else the whole fuckin’ thing breaks.