The general rule that I *try* to follow in situations like this is "first, establish a relationship".
If you're going to make unprompted demands of someone or even give them unsolicited advice, you need to give them a reason to care. There should be *some* level of reciprocity involved. Find a way to support their work. Join a common organization. Develop some resources to *help* them do the thing that you're asking them to do. Just… something. Anything.