All I can say is keep going. I've been feeling the absence of this for a while, and have taken to making occasional videos on Loom to supplement live meetings and Slack messages. But it's a disjointed experience, and Loom is not trying to be a collaboration tool at all. It would be great to have a solution that does the whole thing end-to-end, with a focus on being more async-friendly than Slack.
By the way, I downloaded the PingPong app, and it seems great. Are you selling subscriptions, or just putting the free version out there for now?
P.S. If you haven't read this article on Figma's growth strategy, I'd take a look. There are some parallels with what you're doing -- i.e. SaaS, collaboration-focused, and attempting to dislodge incumbents with a similar list of features, but less focus on collaboration pain points. https://kwokchain.com/2020/06/19/why-figma-wins/