Jacob,
I did use the Companion zip file, without unzipping. Is this the correct source?: https://s3.amazonaws.com/downloads.bluerobotics.com/Pi/stable/ardusub-raspbian.img.zip
I noticed in this post you gave a link to a “sideload” zip file for a manual update- is that needed?
For the PixHawk update- OK, will try v2. (I assumed v4 was the latest update? kind of confusing)
Thanks,
-Scott