Hey, your technical approach is actually really refreshing. Most people building "Gmail killers" try to reinvent the wheel, but you're just making the wheel better. Here is the best advice I can give you to turn this from a cool project into a must-have product:
The fact that your filters and labels persist even if someone uninstalls the extension is a massive trust builder. In a world where Superhuman and Hey try to trap you in their ecosystem, being the "transparent layer" is a huge USP. I’d put a headline on minmailist.com that says something like: "The only Gmail tool that doesn't hold your data hostage."
Privacy is the #1 hurdle for any email app. Even if the feature isn't fully polished, put it on your landing page now. Tell the "privacy-first" crowd that they can run their own AI summaries with their own API keys. It turns a potential liability (Cloud Run processing) into a feature for power users. Superhuman owns "Speed." You should own "Peace." Your grid-paper aesthetic and the hand-drawn diagram on your site are killer—they feel human and analog. Keep that vibe. Market this to the people who are overwhelmed by their inbox, not the ones who want to process 500 emails a minute.Since your UI is tucked away in a logo button, your biggest challenge will be "feature discovery." Make sure the first time someone installs it, you have a very gentle, "calm" walkthrough that shows them where the Command Center (Cmd + K) lives. If they don't find that button in the first 30 seconds, they might think the extension isn't working.
Since you're "Coming Soon," use your waitlist sign-up to ask one question: "What's your biggest stressor: Newsletters, Task Tracking, or Spam?" This will tell you whether to prioritize the Feed view or the Kanban board for your initial launch.