alt Hacker News> There are no "levers".
There are never "no levers" - the best you can do is make sure that the levers you know about are aligned with the purpose of the site.
And that works pretty well. Don't SEO-post, write a blog about some technical aspect of SEO-posting, and you'll do better.
HN-posting successfully can't really be done "at scale" - by design.
Here's a successful formula, but takes some time.
Participate, read things you know about and are interested in. Post comments. Eventually you'll find yourself repeating, or linking to previous comments. Write a blog post about that. Post it.
> "Here's a successful formula, but takes some time."
Have you looked at the very first sentence of the OP's submission? Their investors are not going to wait around for any of that. The OP all but outright says they want a "lever" that they can use repeatedly that pops a marketing submission to the HN front page as a gauge of interest to satisfy investors and secure funding. That isn't reliably possible even for longtime HN users with a solid posting history and high karma (and thank heavens for that or HN would be a very different place).