TLDR; I'm Cheap, use short-charging method.
Given the price of these batteries and in general being frugal or wanting to extract maximum value for money, my preference is to never be in a position of having to discharge the batteries in the first place. So my setup is simple,
1) Keep the batteries at storage most of the time, unless I intend to fly.
2) Use a parallel charger to charge all 3 up
3) Connect parallel charger to remote timer (can be triggered remotely or programmed to turn on) -
4) Charge batteries fully as close to the time I intend on using them
5) Fly them down to ~20-30%
6) Let each battery cool to room temperature.
7) Connect all 3 to parallel charger and charge back up to storage charge
8) Program the timer for a 15min charge and then switch off
Rinse Repeat
The time it takes depends on charger but on the RCGeeks 5A, I can get back to storage levels with ~15min charge, that way it only takes ~40mins to charge back to full when I intend on using them. This way I dont waste cycles on trivial items such as charging my phone/tablet, wasting money on dischargers from Amazon etc.
If they were cheap $40 hobby grade LiPos I probably wouldnt care so much but
Mavic 2 batteries here retail $239AUD each. Works out to ~$1/flight assuming it even lasts 240cycles - thats not cheap. My oldest and most used LiPo had done 110 cycles so probably closer to $2/flight for me.