Harbour is maintained by a small team. A real person reads what you send.
Three places, so your message reaches someone who can act on it.
Open a GitHub issue. Include the page, what you expected, and what happened instead. A failing build log is worth more than a description of one.
Email us. Tell us what you are trying to compose and what the build said when it refused, and we can usually point at the rule rather than guess.
Email us and say so in the subject line. Licensing, support, and work-for-hire all go to the same address and get answered by a person, not a form.
Within a couple of working days for email. GitHub issues are triaged less predictably, because they queue behind whatever is being built that week. If something is time-critical, email and say so rather than waiting on an issue.
Sometimes. Harbour is a template rather than a service, but the team that maintains it does take client work. Email with what you need and roughly when, and you will get a straight yes or no rather than a discovery call.
Not as a product. The template is MIT-licensed and comes with no warranty, which is stated plainly in the licence. If you need something firmer than that for a client engagement, that is a commercial conversation and the answer is the email address above.
Yes, and the useful ones arrive as a description of what you were trying to compose rather than as a proposed API. A Block that solves one real page tends to be the right shape; a Block designed in the abstract usually is not.
Clone it, edit the content in git or through any AI agent, and ship your own site.