Not possible to completel delete e.g. the Query part of a URL via plugins

If you use an API call like

TSUrlHttpQuerySet(rri->requestBufp, rri->requestUrl, "", 0);

the resulting request will still include a '?' e.g.

GET /? HTTP/1.1

I believe the same is true for other similar URL APIs matrix parameters and port. We really ought to have a way to completely delete the component.