Per T328559 we want to make internal calls to parsoid directly to the endpoints exposed by the extension, instead of going through RESTbase.
cxserver is currently sending about 150 req/s to parsoid. Switching it over would be a good test.
Potential issue: without the caching layer in restbase, latency may be a bit higher.
See https://github.com/wikimedia/mediawiki-services-cxserver/blob/master/config.prod.yaml#L72
See also the similar issue described in T311867.