RE: TTML Schema Verification

> Any chance they are really trying to conform with a subset profile such as
SDP-US or CFF-TT?

We are seeing obvious schema issues like this: tts:textAlign="after".  Also seeing the positioning model below that does not appear to be a schema error, but is not defined in the spec:

<p begin="00:00:01.40" end="00:00:04.13" region="speaker" tts:textAlign="right"><metadata ccrow="12" cccol="8"/>[crowd cheering]</p>