Can't do any quick shots and it's also complained about landing and other things.I get the same warning on my iPhone 6. I've just ignored it and have not been aware of it causing any problems with functionality. That being said, I haven't tried testing all functionality while the warning is active. Next time I see the warning (and it's safe) I will try to test a few functions that may be more computationally intensive (i.e.; RTH and Quick Shots).
Hopefully, if I remember to do the test I will also remember to report on the results. ?