(Author here)

What I've learned, after hundreds of convos with developers sparked by emails like this, is that many people are happy that someone from the company is interested in their project and their opinions.

Those who feel that way are glad to get this and they're glad that there's no burden on them to get on a call or schedule a zoom or fill out a questionnaire or even click out of their email client.

And those who don't want to be bothered, well at most they've lost 5 seconds of their day to read the email start to finish.

In other words I think this fairly symmetric... Low effort and high value on both sides.