I can not answer as asked..
That said, imo, the best 3.6 program is what works for an appraiser now. One can always upgrade or change software later. Since so much about 3.6 is new and need a learning curve, it makes sense imo to use the software one is familiar with and has to get the first batch out.
I see a lot of overnight companies claiming to be awesome. The reality is that ALL of them will use the same 3.6 drop-down download format. There is no way to avoid it. The 3.6 format is GSE-driven. The difference is that some of the new software companies claim to be "built for 3.6, AI-ready."
Most major companies, such as Alamode, can accommodate add-on programs that auto-populate or that incorporate AI software.
Personally, I would be nervous about some of the one-hit wonder overnight Insta companies. Will they be around in six months or a year? Do they offer live support, or just chatbots? How secure is your data with them? Do they provide other forms, or just UAD 3.6?