Re: Streams - still not entirely clear to me what they are. One way to frame a new feature is to explain the scenario first, and then how the feature solves that pain, and then naming it. So it might be something like:

"If you struggle with grouping your notes from similar meetings together so you can find them easily (scenario) we solve that by using Streams in Hera (which are basically tags). So you can easily click on the 'onboarding' stream to see notes from all your onboarding meetings in one place. This is helpful when you're trying to xyz."

Also if streams == tags I'd think hard about whether to introduce a new name for an existing concept that all of your users already understand... unless it truly is a different concept.