Here is my experience. Everything here is purely my opinion and may be right or it may be wrong, but this is the story from my point of view.
At the request of the dealer. I took my FXS to him, July 20, 2020.
August 21, 2020 the dealer told me Zero had finally been able to connect to my bike and they believed that it needed either a controller(~$1500) or motor(~$3000), but we had to wait for Zero to have a meeting the following Monday to decide for sure. Not being able to make an immediate decision, based on the diagnostics report does not give me a feeling of confidence in Zero. It feels to me like they are just guessing and wanting to throw expensive parts at it in the hope that something might fix it. Somehow it had been determined that commissioning or alignment wasn't the problem.
August 26, 2020 I picked the bike up from the dealer and paid them $160 for their time (Actually, that was a low price for the diagnostics effort on their part.)
At that time, the dealer told me it had been decided (by Zero) that a new motor was needed. Because of its age,(2016) the bike is no longer covered under warranty. So,,, now I have a bike with 1707 miles on the odometer that Zero says needs a $3000 motor replacement. It does not make good business sense for me to spend the additional money on a bike that I paid $4500 for when I bought it. Rather than spending more money on the Zero, I have invested the $3000 in a beautiful Honda CRF230L that has 1450 miles on it. It will be reliable and will serve me for many years and, if it breaks, I can fix it myself!!!!!!
What have I learned? A used Zero might look like a good deal, but if it breaks, you might have a very expensive pile of useless junk. BUYER BEWARE!!!