I also love Intercom. I took their Jobs to Be Done methodology and made a value prop project out of it! https://www.intercom.com/books/jobs-to-be-done
I also think stripe has a great website for their products and reference it frequently: https://stripe.com/
Segment has pleasantly come a long way - they have a clear explanation of who their product is for, use cases, etc: https://segment.com/
The early work Twilio did to quickly convey what the service did and who it's for then get developers to dig into the product and have an a-ha moment with a couple of lines of code was pretty great. All of it tic and tied back to the brand and voice of the company, which had a sort of open source community vibe despite being a commercial entity.
Great question that's very top of mind!
The broader GTM organization will own the growth targets, while the broader Product organization will own the adoption targets. I believe where tech PMM can make the most impact on both sides of the house is with velocity targets. On the GTM side, that's things like sales cycle velocity. On the product side of the house, that's things like onboarding velocity. The content that gets created by tech PMMs should be an accelerator, so the KPIs should match accordingly.
I don't have a recommendation on the group, but a good next step if you don't get an answer here would be networking with a couple of PMMs at companies that sell to/engage with developers to get their perspective. Folks at Atlassian or Github, for example, could probably give you some really great insights.
One suggestion would be to see if you have any talented sales engineers that may want to make the move. These individuals have spent a lot of time speaking with customers, understanding their technical needs and frustrations.
It is not always the case that you will find an ideal candidate there, or want to "poach" someone from that group, but just something to keep an eye on as they already know your company and customers well.
If buyers are complaining you should listen. The art of messaging is not to be flashy or buzzy or trendy, it's to know your target audience and speak in their language. If you've heard some negative feedback take a moment to look into it, find out whether that is the view of the majority of your buyer personas. If you find that to be true, it's time to change how you communicate with your audience.