Are there several, or is it time and time again? I'm confused, as you made it seem like there had been an epidemic of aftermarket battery related crashes, which was something I'd not heard of.
Ask yourself this...
Why do you want an aftermarket battery? Lower cost?
Also ask yourself this...
How many times have you read about random fly aways or unexplained crashes?
Do you know whether or not they had an after market battery? Does the DJI app tell you 100% that the battery, or the prop, or whatever is the cause? No!
Based on how many people defend aftermarket batteries in this thread I'm willing to bet that several crashes / flyaways had them.
I'm not saying they were caused by the aftermarket batteries at all but neither do do you. To be honest no one will ever know.
However I am saying that at least if you have a genuine DJI battery you know its up to their standards and you can for one rule out it being a cheap corner cutting battery.
Plus again DJI can see the battery serials in the logs, why would you want to give them an excuse to blame your battery in the event something happens?
Say your DJI battery catches fire and burns your bird or even causes property damage. You have some leverage and arguing points since its all DJI stuff.
Say that same situation happens and you have an aftermarket battery. Guess what they are going to say. "Your bad for buying that battery. Take it up with the manufacturer of that company. We have disclaimers stating to use genuine batteries"
Lastly have you not seen videos of LiPo battery fires? There are reasons people buy LiPo storage boxes.
It is common knowledge that LiPo batteries are a fire risk. Why buy an unknown aftermarket one.
The way I see it I would rather spend the little extra to make sure I buy a battery that was designed and tested by the same company that made the product.
Yes I know the battery is sourced by DJI to another company to make it that's how manufacturing works. It still was designed and tested by DJI etc.