You're welcome to trust that there's nothing bad in the app, or that their security internally is super top grade and a 3rd party hasn't injected their own fun into the code. I work in security, and this is simply the most blatant example of bad procedure I've seen from any otherwise reputable hardware vendor.
There's no valid reason for them to bypass the checks of any application store, and even the lord of the flies Tim Cook has made that abundantly clear in recent times. The fact that they have made such a choice is in itself a reason to not trust them, full stop.
And since there is no reason whatsoever to justify paying an Apple tax, buying into that hardware/software realm isn't an option that's worth half a second of consideration.
Direct APK downloads can contain literally ANYTHING, and there is absolutely no 3rd party security validation, or checks and balances.
Wanna buy my
M2P since you're okay with this? Luckily for me, there's a DJI store right down the street that will happily resell my used gear, and that's precisely where it's going. It's a great drone, but no drone is worth throwing away the most basic of security for.