Often when I report something as slop, I'm doing it because I can see several results with nearly identical wording next to each other. It's really obvious that something fishy is happening when you have this context.
For example:

(Note in the above I have my settings set to exclude slop results, so these are sites that just haven't been caught yet).
I suspect that the review of reported sites may already take this into account. If so, maybe this is just a request to note that in the documentation. If not, then I think it could be useful.
How it affects my UX: If it makes it easier to detect and remove slop results, it would help keep the internet as open and searchable as we all dream it to be.
Maybe an additional button on the SlopStop popup that lets you add other entries from the search results to the same report.
Alternatively, if the search results are available to whatever process reviews these reports, maybe they could be automatically used to evaluate the report and removed alongside the offending domain.