Finally got something tangible together and published a very simple landing page with mailing list subscription form at https://leanflags.com. The page is definitely barebones still and I need to add quite a bit more information there before I can expect actual signups. I took full advantage of undraw.co and their "Evie" page template. The mailing list is using mailchimp for now, and that turned out to be surprisingly tricky to get integrated in a nice enough way.