Hello! I don’t need any support and don’t have questions, just wanted to share my experience and provide a data point. Thank you to CyanLabs for this awesome community.
Back-back story: I used to have a 2014 Explorer Sport with Sync 2. Sourced a new APIM + Screen, used Syn3 Updater and it was wonderful. Then, I sold the car.
Current Backstory: I have a 2016 Fiesta ST (non-nav, 6.5" screen) that I recently purchased & updated Sync manually from Sync 3 version 1.0 (forgot the build) to 2.2.17011 (using a non-nav link I found online) to 3.0.20204 from Ford. The reason for this was because I read stories of folks jumping from 1.x → 3.x and CarPlay not working. After manually updating all the way to 3.0.20204, my new hub came in (HC3Z-19A387-F) and CP was working well. I then used Syn3 Updater to upgrade to 3.4.23188. Things worked very well, but…
…Well, I found a crazy deal on a 2016 Fiesta nav APIM + screen (g1bt-14g370-cl) on eBay and wanted to get factory nav in the car since it was so cheap. I bought the Fakra blue antenna (XT91835) & started the install today. Total cost for APIM+screen, GPS antenna, USB hub/module: $130. I might sell the factory non-nav APIM+screen to put it towards other goodies, but will hold off until I’m certain this used unit won’t act up in the near future.
The nav APIM came with version 1.0.15139. I tried following the same steps as before, updating to 2.2x → 3.0.x manually, then 3.4 w/ Syn3. This didn’t work. I tried 2 different flash drives and two different files to get to 2.2, but it would just hang up on “Updating system software” even after 1.5 hours of idling, and would also throw the “USB not supported” error, even though I had the new USB hub already installed. The first set of files I tried was found on the F150 forum specifically for nav units. Previously, I had used the non-nav one without issue (as described in my “current backstory”). After the install was hung up, I pulled the flash drive, turned the car off/on, closed/open door, master reboot, etc. and tried only updating with the 2.2 APP file from CyanLabs. This didn’t work either.
I was reluctant to update from 1.0.x → 3.4 since I saw a bunch of threads about CarPlay not working, but I realized a common trend was folks were updating it from Ford, not Syn3. One or two threads mentioned that you can do this with Syn3 without any issues. In fact, one person had lost CP when updating to 3.0.x (skipping 2.2.x), and ended up using Syn3 to get to 3.4.x, where CP started working again.
Just wanted to document my process in case it helps folks in the future. There were a ton of files, but Syn3 updated my “new to me” nav APIM from 1.0.15139 to 3.4.23188 in a little over 30 min. After I pulled the flash drive out, the APIM rebooted and the maps/nav kept trying to load, but I was impatient & performed a master reboot. After this, the maps started working immediately.
CarPlay works, stock navigation works with 2022 maps, and I’m thrilled. I restored my original non-nav APIM AsBuilt file & made a change on 7D0-01-02 to the second digit to enable navigation on my stock APIM asbuilt values: from x0xx xxxx xxxx to x2xx xxxx xxxx. (Thank you random post on Fiesta ST forum).
And of course, I updated 7D0-02-01 from xxxx x1xx xxxx to xxxx xBxx xxxx to show off the ST splash screen 
(Thank you another random post on the Fiesta ST forum).
But really, thank you to the folks at CyanLabs for the documentation, support, and generosity to the Ford owner community & coming up with all of the resources to modernize our slowly aging cars.