Given that we basically said we'd support the heading bug out of the HS34 via ARINC-429, that's a pretty unique definition of "deafening silence"
In any case, we try hard to not make promises of future support when they aren't actually being worked on. Other company AP support is not currently something that any engineer is currently working on, so we're not promising it. Unlike many other companies, we want you to make a purchase decision based on what we do today, not what we might do in the future. This loses us specific sales sometimes, but we think its worth it in the long run by not disappointing anyone.
There's actually a great example of this from our past. About 2 years ago a customer had a D100 and a D120 on order from us. At that time we didn't do an HSI. He called us and canceled his order because we didn't do an HSI and a competitor promised they would be doing an HSI when the product shipped. We told him we were sorry to lose his order, and we wished him luck, even though we were working on the HSI internally at that point. 3 months later, we shipped the HSI as a free upgrade for every customer. It took him 6 more months before he even got his unit from the other guys, and then he ran beta software for months.
That customer now works for us as an engineer.
As for the ease of implementing this, Dynon works VERY different from other companies in the Experimental EFIS sector. We don't release stuff unless we have tested it over and over. So a release process for us requires us to write a spec for a feature, implement it, then go through 2-3 months of beta testing. Then we have to document it. Because of this, every feature requires tons of work on our end, no matter how many lines of code someone on a forum guesses it to be. A feature is a feature, and it requires it to be implemented to our standard.
Because of this, our forum isn't full of people asking about bugs or features they were promised months / years ago. People don't need to ask how to use or set something up because we actually have manuals for all of our features.
It should be clear from this discussion that Dynon has considered this support, and for now, we have not considered it a high enough priority to implement. We've had engineering discussions about what it would take, and you'll just have to trust us that it isn't 3, 30, or even 300 lines of code, and even if it was, that's still lots of hours for us when you consider the whole process. Given that Dynon has actually made a UAV that can fly for hours, over the horizon, on its own, then come back, should tell you that we have a pretty good sense of the complexity of this issue. Linear systems do not make an autopilot.
We're sorry if our current product doesn't fit your needs. A quick glance at this forum beyond your first two posts in this thread will show you that Dynon is actually a very customer focused and responsive company. There are tens if not hundreds of features we have implemented based on feedback. Many of them show up as "surprises" in releases, since we do our best to not talk about stuff until it's done. Maybe someday we will fit your needs better, but if your primary need is a heading bug driven over to the AP, we're not your company today. At least we're honest about that. If your needs involve honesty, incredible support, unbeatable prices, proven reliability, software stability, or quick shipping, you're not going to find any experimental EFIS manufacturer that beats Dynon.