The glue one was proven to be just a troll comment on Reddit from 12 years ago, and it fact some more were found to be just basing itsself on Reddit. Fine in theory, but did absolutely no proof check with other sources and so just took trolls as facts.
This is how GET works, every single parameter is visible regardless of meaning.
How about https://addons.mozilla.org/en-US/firefox/addon/clearurls/ ? I use it on default settings. There is a chance you can set it up to clear StarPage’s GET variables too.
But if there is an actual setting to use exclusively GET parameters by StartPage, they will just be populated again.