Too late now but you can turn off auto updates at least in the Android version.
While some of the incremental changes are no big deal every now and the a big change is made which can result in enforced updates to the controller and phantom. 
On balance all on latest firmware is probably best but if you get an unexpected mis-match while away from wifi you can be grounded.

There is no obligation to update anything, you can ignore the (scary looking) red banner that pops up when you switch on indefinitely.