TransportOption unavailable for MetadataProvider MDQ?

[Paul Barton]

I'm interested in proxying connections from shibd. In the past I was
able to use a TransportOption inside MetadataProvider when using the
"XML" type:

<TransportOption provider="CURL"
option="10004">proxy.example.org:8080</TransportOption>

We transitioned to using the "MDQ" MetadataProvider some time ago. The
documentation doesn't state that TransportOption is available with
this type, though shibd does reload/restart successfully if a
TransportOption is placed within MetadataProvider. I verified that
even by placing TransportOption within MetadataProvider type="MDQ",
the connections are not proxied.

Does anyone have experience proxying shibd connections when type "MDQ" is used?

Thank you,
-Paul