Just be respectful and not snarky. And be clear about your boundaries. What I do is I add the following notice to my GitHub issue template: "X is a passion pro

Just be respectful and not snarky. And be clear about your boundaries. What I do is I add the following notice to my GitHub issue template: "X is a passion project and issues are triaged based on my personal availability. If you need immediate or ongoing support, then please purchase a support contract through my software company: [link to company webpage]".