Lightroom Classic: Could it made possible to disable face recognition for specific folders or collections or via toggle switch?

You could turn off face tagging at the catalog settings level and request face detection/recognition on-demand on a source selection (folder or collection) basis while visiting Lightroom's face view. Since Lr 7.3, you could also choose to find faces manually via the "Library>Find Faces Again..." command on selected photos.

Thanks for that.  I may try this, but I have hundreds of folders and collections I do want to auto-find and only a few collections I don't wan it on.

The other challenge, although this may be the case whatever solution is created, is that I still want to tag and have FR on the original image - but just not on the virtual copies that are specifically for Stock.  So if I turn off FR at the catalogue, and then put it back on for a folder containing the photo of family/pets, then it seems to still include any virtual copies associated with the image - and I'm back in the same boat.  Whereas if I could toggle it off for certain photos / collections then I could just select the virtual copy in this instance and switch it off whilst unaffecting the original image.

Thanks again for your time.

The "Library>Find Faces Again..." menu command will work off the current photo selection. You could leveraging Lightroom's existing filtering mechanism (ie source selections and various filters) to target specific set of photos that you want to run FR on. Here is an article that describes to filter out virtual copies http://www.lightroomfanatic.com/tutorials/beginner/finding-virtual-copies-in-a-library-haystack-using-filters/

Thanks again. It sounds like I can work around it to an extent - but it seems you're saying that there is no means by which to switch off FR for certain folder/collections/photos - the only option is to switch it off for the whole catalogue and then go in and manually run the FR for the ones I want it on (over 95% of many tens of thousands). To do this I'd need to filter these folders to remove the virtual copies to run the find faces - and then I'd need to filter the inverse to go through the virtual copies and find the ones that are personal and not stock and run it on them also.  Plus whenever I import new photos (I have several sources - lightroom mobile, an auto-add folder, plus importing from the various cameras) I would then manually need to run FR, making sure I create my stock copies first and filter these out.

So I think at the moment that would be far more work than just trying to keep an eye on my stock photo copies and trying to make sure that I don't tag people accidentally and submit these details to stock companies.

I do think it would it be good if Adobe could consider a toggle off for FR for either directories or collections or individual pictures.  This would not just help me with images being submitted to stock agencies, but also with crowd/landscape shots - as mentioned here by Wolf and Kent and Tudor or here by Robert or here by pfredd, and also with wedding and professional photography as mentioned here by crsouser and again here and here. Is it possible to submit this suggestion to Adobe?

Thanks so much.

Agree with hpphotos.  An example is a shot of an orchestra.  I really don't want to do facial recognition on 100 people in that photo.