This isn't helpful, but I've had a surprisingly high success rate with cold outreach when I didn't have a need or expectation of a response. But then, I also te

This isn't helpful, but I've had a surprisingly high success rate with cold outreach when I didn't have a need or expectation of a response. But then, I also tend to email researchers (and generally not the ones involved in some big breakthrough, just more niche ones that did something that I found personally very interesting.) And researchers are generally pretty happy to find out that anyone is interested in the topic they've poured their time and energy into, especially if you're not just asking the obvious followup questions. So I've mostly gone after soft targets. I also have a habit of contacting higher-ups of the institutions I'm associated with (my company, my kids' school, etc.). Usually with jokes. Sometimes with complaints, in which I say things that I really shouldn't be saying if I value my job, but a little honesty and reasonableness seem to go a long way. Quite a ways from what you're looking for, but the same rules probably apply: if you have something to offer, even if it's only your rapt attention for a topic of interest to them, then tell them up front in the first sentence or two. No tricks. Be honest. Make it easy for them to decide to not respond as quickly as possible (rather than eg hinting at things or being ambiguous, hoping they'll interpret things in the most favorable light.) Value their time, and express that in how you write the email (but not by saying "I know how important your time is" or whatever. That's bullshit. You value someone's time by being efficient and not wasting it.) If you're just asking for their time, you're doing it wrong. Why should they give it to you? Tell them why they should care first, then put your ask after. It's best if you really do have something of value to them. Then your email just needs to effectively and efficiently communicate that.