So this feature request is in response to what has been discussed in topics like these?:
https://forum.inaturalist.org/t/computer-vision-mistaking-plants-for-arthropods/53634
https://forum.inaturalist.org/t/leafminers-have-broken-the-cv/54378
I like this. It feels like an elegant and useful fix, and having a little iconic taxon symbol next to the name would I imagine at least help somewhat in those cases where an inexperienced observer wants to ID a plant but the first CV suggestion is a leafmine or mildew with no common name.
I also think a way of being able to initially limit the CV to an iconic taxon of the uploader’s choice (or have headers, as you suggested) would be very helpful (I know you can do this in the suggestions tab of the ID interface, but it would be great to do it while uploading on the website). If a plant is absolutely covered in leafmines or galls, it’s my experience that the CV will often not give a suggestion at all for the plant, which is unfortunate, since noting the host plant is often essential for IDing them.
However I would say, in the example you gave, there is white discoloration on the leaves, and the powdery mildew suggested (Neoerysiphe galeopsidis) is found on Glechoma hederacea, so even if that discoloration isn’t powdery mildew (not my wheelhouse), in this case I’d probably ask the observer if they were interested in IDing the discoloration or the plant, rather than assume an ID counter to what they suggested. If there’s, e.g., a leaf with no visible leaf mine, then IDing the plant (with a comment noting that you don’t see a leaf mine) seems appropriate.