Yes nice to discuss!
Sucks with your FX pack.. but happens..
I have one more thing to add. You're right with how to use a battery, but there's a point around 55% (called the central graphite peak in the differential voltage spectrum), above which cell aging is significantly higher. 5% seems like nitpicking, but it really makes a difference. It's not too big but since it's only a 5% difference to the end user, I just wanted to say that. Don't store at 60, store below 55 or 50, to be sure.
Also I checked and it makes a difference how high you charge, even if you use it immediately. It's a pretty significant difference, so I strongly recommend only fully charging if needed.
On the other hand, we buy the bikes to use them, and Zero charges them to 4,15V only, instead of the usual 4,2V for exactly that reason.
But yea.. It makes a big difference, avoid if you can.
I didn't come up with all that knowledge:) it's taken from a study of NMC batteries (exact same chemistry that Zero has)