Can I exclude a specific Download Categories/Tags when generating Upsells?

Yes. There are two ways to do this:

First, is by going to the Settings Page > Algorithm Logic > Exclude Categories / Tags. Here you can enter the specific Download Category or Tag that you want to be excluded when generating Upsells throughout your website.

Another one is to go to the specific base product, scroll down to the page, and enable exclude and define upsells you don’t want to be generated for this base product.