I believe you are overthinking things. These aren't hard to overcome problems. Batteries are fundamentally very simple and they are designed to handle wide variations. Simple enough that there are already a bunch of shops that will rebuild and restore batteries using volt meters to yank (and sometimes replace) bad cells.

As for the factors affecting battery life, it's looking like age above everything else is the primary killer of batteries. Temp is a solved problem, all modern EVs have a cooling/heating system.

Cell phone batteries are also different from EV batteries. You won't find a cell phone with an LFP. that's because cell phones target energy density above all else.

As for travel charging, 15 to 25 waits are typical and charging past 80% is slow. A battery at 10% can accept 350kW of power. Batteries are 80% typically can't accept more than 80kW or less. The 80% to 100% time can take twice as long as the 0 to 80 time.

Waiting for a charger to be available is an infrastructure problem. I've had to wait on gas pumps to be available during busy times. Conversely, the most I've waited to charge has been 10 minutes (and I've traveled every thanksgiving for 7 years of EV ownership).

The 20 minute break is welcome after driving 2->3 hours.