I was hoping a standard procedure for reporting a page you aren't actually on could be implemented.
This is not the concept. If you report a thing, you have to know what you are talking about, so you will be at the page where the report button is. Making a new concept will not be done, because there are already two other methods of contacting itch with issues you want to tell them. Contacting support and clicking feedback. Posting in the forum is not such a contact method - this is a way to talk to other users.
From a pragmatic viewpoint, why and where would they even implement such a concept? Put a button next to "contact support"? It is what the admin told. There is need to connect your complaint to the item you complain about. If you have no connection it boils down to writing informally and that is already fully implemented with the contact support button.
Regarding word usage, if you search for clickthrough meaning, you will get that it is an alternate spelling of click-through. And if you search for that you will get this:
click-through
noun
An online advertising performance metric representing an individual responding to an ad by clicking on it.
Note, there is only one meaning in that dictionary. I tried another search engine.
click-through
nounCOMPUTING
the action or facility of following a hypertext link to a particular website, especially a commercial one.
Is this a translation issue? I do not know if there is a catch-it-all term for nag screens. The age confirmation in this case.