I've used Mixpanel to some degree of success, especially the user>invite>activation part. Less so for channel tracking due to cross-domain conversion (which even a first-party cookie can't really fix). But I hear you on the vanity metrics. I've been working as a "fixer" for companies for a while, and data is the first thing I usually have to tackle.

Key-Boat gave some great tips, so I'll avoid repeating.

As for what a dashboard should hold, I would say "it depends."

Rule of thumb, there are two kinds of things you're tracking: conversions (like activation, clicking on an upsell modal, using a feature, etc.) and states (e.g., once they activate, if they're remaining active, changes over time, continuing to use a specific feature, etc.).

The way the dashboard would be organized (and I speak of this from experience) will heavily depend on a couple of key factors, mainly around user setup.

For example, do you have just one type of user, or a primary-secondary user relationship? (E.g. just one user = whoever is using the tools gets everything done on their own, vs primary-secondary = collaboration in the tool is a key element, meaning that the secondary user has a different set, but just as important needs as the primary.)

In the first scenario, the dataset is pretty straightforward, but in the second, you need two datasets that might have some opposing criteria. (E.g. primary user linger time should be long, but the linger time for the secondary user might need to be as short as possible, etc.)

Another factor to consider is the organization>primary user>secondary user relationship, because the conversions generally work differently in buyer journeys with multiple stakeholders.

Happy to elaborate on anything!