We use Evernote Business for a few projects and we run into this exact issue. It's a bit clunky to have a discussion in the note itself. I would rather see something like comments on notes as a premium or business function. There are 3rd party apps like Basecamp, Asana and Slack that offer this kind of discussion, but lack a good integration of Evernote Business. Right now we use Google+ to discuss and collaborate on projects and use Business to share files and ideas. Not the best way of working....