Scott, first, congrats on your first flight!
As an FYI, the FAA will never publish a document that they state that an experimental product complies with the law. That's the point of the TC, STC and TSO process, which we all know is expensive. They can't make that statement without analysis, and they do that analysis under a TC, STC, or TSO. It's like asking them to state that a Vans RV-X design is compliant with the FARs. Even a TSO is technically a self audit, with the FAA poking their head in now and then, and the FAA has that ability to revoke in the future if they find out something went wrong on that process.
It's easy to forget as EAB owners, but the Navworx issue came out of the TSO process. Our understanding is that Navworx had a TSO, but then changed the product without getting requisite FAA approval. They actually HAD approval and then ended up with it revoked because the product changed. So getting an FAA statement is no guarantee, you also need to trust the company you are buying from. Same thing happened to Ameri-King who also had a TSO and behaved badly.
What I can tell you about Dynon is that we have been a leader in ADS-B compliance, and take it very seriously. We have voluntarily worked with the FAA to ensure we meet their requirements, even if we have not done it under official TSO or STC. We have a deep analysis done on our GPS position source, as well as the system as a whole, and how it complies to the FARs, and we have all this documented if any regulator needs to audit it. The vendors we use all have deep experience in TSO'd products and certification, and sell their products widely in the aviation industry. We've been on industry committees to help shape ADS-B, we've worked with the FAA to help them draft the guidance on ADS-B in EAB/LSA which would otherwise be in regulatory limbo. We were ahead of the curve when the FAA announced changes to traffic and ADS-B in 2015 because we had been part of the committee discussing those changes with the FAA (as had navworx), and we were able to give our customers a software update that kept their traffic for free even in a changing regulatory environment that other vendors struggled with.
You'll notice that all the experimental GPS position sources from Dynon and other experimental companies carry a statement that the company has evaluated them as being compliant to 91.227, and that's because that's what the FAA expects, based on this guidance:
https://www.faa.gov/nextgen/equipadsb/faq/#q4. The FAA is allowing companies to self-declare their compliance, which lowers costs, but it does mean you need to trust the company and their ability to actually do this, resolve any issues that do occur, and to be trustworthy. If you want the FAA's guarantee, you need to buy TSO/STC, and even then, the company matters. I think Dynon's 15 year history in experimental aviation shows that we're a company you can trust to keep your airplane compliant.
--Ian Jordan
Dynon Avionics
P.S. As a final note, compliance in an EFIS system goes beyond the GPS source. The ADS-B system as a whole must be analyzed. Even if the FAA finds that a GPS is acceptable, that doesn't mean it's acceptable when hooked to any random ADS-B out transmitter. Make sure your vendors list compliance of the whole system, not just one part.