I'm curious, what does having control over the update process give you? Isn't it replacing one unauditable black box system for another?
Are you concerned about a regression and don't want to be in the vanguard cohort?
If by "vanguard cohort" you mean "in the first wave to test the new software," then yes; I don't want to be in that group.
They're entirely different products, costs, use cases, risk profiles.
The ForeFlight team will send out a message giving an "all clear" or a "wait for us to update the app before updating to the next iOS/iPadOS release."