Well the answer is A. Discharging to 10-20% would both increase the number of discharge cycles unnecessarily and is too low a level for LiPo battery storage. You should probably stop wondering and start learning about this stuff before you do any more flying.
Definitely Option A. Option B could cause other battery issues. This is a complex computer-controlled flying machine! The very least someone can do is read the entire manual and learn about the systems before flying it.
If your automobile engine seized because you never change the oil, is that bad design from the automaker? Or is it not being properly used and maintained as is clearly stated in the user manual?
If you have had the drone for over a year with 40 cycles and still dont know anything about auto discharge,storage levels or cell balance your batteries might not be in as good a condition as you think