While I don't believe it to be the unit directly, I do believe something is going on that changes settings. This has happened to me twice now. Only during initial build. Once it is set up and it is working, I have no concerns.
I have maidened the Spirit twice now. Both times settings work on the bench and both times I make sure to save settings. But then both times I had wrong gyro settings when taking off first time causing a blade strike.
First time was on my Mostro. I had two others check my gyro and piro comp and all 3 of us agreed it was good. Made some other setting changes with android BT (can't remember what but know I wasn't in the servo direction screen). Go to take off and aileron was reversed and destroyed main and tails. Piro comp was also wrong. A friend had spares and I was able to reverse settings in BT and it flew fine. Kept checking gyro before every flight for awhile and never an issue again.
Now I just moved the Spirit to my HD Cell 500. Set it up on PC just like Mostro. Made sure bench was correct and saved. I was all the more cautious remembering Mostro. I clearly remembered I reversed the ele channel to make it work right. Log in with BT before maiden to change some advanced settings and gains. Go to take off and immediately crash destroying mains and tails. I check settings with BT and ele was no longer reversed.
In both cases the mistake I made was not re-checking the gyro before taking off after connecting the battery before the first flight.
To me the reoccurring theme is the BT module. Both times I logged in with it and made gain or advanced setting changes before my maiden. And correct me if I'm wrong, but I do not believe the android app is made by the Spirit team? At least that is what I gather from the donation prompt on it that he does not benefit from the sales of Spirit. I'm also very familiar with PC FBL setup as I use 3SX. I understand the importance of saving and the screens aren't foreign to me.
Morale of post: Always re-check before first flight and after first use of connecting with BT. After that I've never had an issue with settings and fully trust Spirit. As I said to my flying buddies, Spirit and I may not agree on how to setup, but after we work out our differences we get along great