Wow. I love how you went vertical.
The lure of a vertical spit, and making real T-A-P, have been haunting me for years. The history and similarities between TAP, Shwarma and Gyro are very interesting. I almost bought a commercial stainless steel autodoner gyro roaster at auction last year - the price was great - but good sense prevailed.
I have wondered how much the pineapple enzymes add to the tenderization - beyond the flavor contribution.