The goal seems laudable but this feels like a mess to me if it is actually "open for business". Neither of my two big bank brokers support it and even if they did, I again have no idea what I would be investing in.
To me, the wildest thing is that in order to find out of I could even invest, I had to find out via a bad UX of reading a hacker news comment, going to a different website, being confused by that website's UX, having to read more comments, clicking into a tiny link that leads to a long PDF and scrolling to a specific page, and then repeating for all my broker options. Why not just list the major people who serve LTSE on your website clearly along with the tickers/companies?
Scroll down to page 9, you'll see they are a member of The Long-Term Stock Exchange
100 milliseconds is practically an eternity
You can do 2) through your existing broker, so long as they are a member of the LTSE, which they likely already are. You can check their membership status here: https://brokercheck.finra.org/