My original comment wasn't intended to indicate that there is an obligation to provide support. The deliberate choice to: a) not offer paid support for open-source deployments, and b) sunsetting the Kubernetes deployments in favor of their cloud version, is a signal that shows PostHog doesn't /really/ want you to be running the software in a self-hosted manner.
Just look at the "Open-source hobby deploy" (from the README in git) which calls out that it "should scale to approximately 100k events per month" but their cloud offering gives you 1 million events per month for free. What is the point of the hobby "deploy"?
Back to OP -- my answer is yes, this is a source-available service that you can modify and play around with locally. The source and documentation behind the operations of PostHog aren't available.