How does the upsell funnel work when you put it on the thank you page? I've tried adding the upsell to the default thank You page but I don't want it also to appear on the thank you page of the upsell course so they see it again. Is there a way to add it to the thank you page for just one course?
At this point in time, adding upsells to the checkout thankyou page adds the same upsell across your whole site. I can definitely see why you'd want to have product-specific upsells so I'll flag your request for our product team.
For now, one option would be to customize your course welcome emails to include links to specific courses that you'd like to upsell (sorry as I know that's not quite the same).