Mavic 2 zoom multi charger

[Physopto]

Most if not all of the battery charging is controlled by the battery itself, so in theory the so called charger shouldn't affect the life of the battery. It's effectively just a power supply. If a third party charger was the cause of damaging a battery, I'd be curious as to why.
The only criteria I can think of is that some have found/suspected some third party chargers putting out a lower voltage than OEM charger, so the battery reaches 100% at a lower capacity than it's capable of, but that shouldn't be permanent, and actually could prolong the life of the battery.

Swelling tendencies for the M2 batteries based on statistics seem to gravitate towards:
First few batches of batteries manufactured (July/August 2018)
High storage temperatures (the most reports were in last year's summer months)
Leaving batteries fully charge too long, particularly in conjunction with being stored at higher temperatures such as trunk of a car while left fully charged.

I have a Samsung laptop and it restricts the charge to 80% all the time. I am informed that this is to protect the battery from overcharge. So in effect 80% is 100% as far as Samsung is concerned. I believe it can be overridden in software some how by re-flashing the charging parameters, but why do that at the expense of maybe screwing a good battery. I also read on several web pages about LiPo batteries, that constantly charging to 100% does the battery harm in the end as you can easily overcharge the battery unintentionally if the charger allows the voltage to go over the maximum value of the individual cells. I would expect as the LiPo batteries have evolved over the recent years that this is now something in the past. Still £129 per battery here in the UK is a lot to loose!
I agree about undercharging LiPo being not a problem. It is different for Lead Acid as repeated undercharge completely screws these batteries.
Just as well we now have the newer types or drones would never have come about.