RenderUnsupportedPdfFeatures: what turning it off buys, and what it costs

Builds two throwaway documents from the same PDF bytes — A at the default (true, how every template in the catalog was made) and B with RenderUnsupportedPdfFeatures = false — and compares them. Both documents, and their pdfs rows, are deleted before the page renders. No live template is touched.

?id=50045 — read-only census of a live document, creates nothing
?uuid=2D8206A  |  ?alias=tplFile-X.PDF  |  ?file=C:\path\x.pdf — the A/B comparison

pass one of:
   ?uuid=<templateUUID>   e.g. ?uuid=2D8206A   (reads tplFile-<uuid>.pdf)
   ?alias=<blob name>     for a template whose fileAlias is not canonical
   ?file=<path on disk>