If you take a look at the perf. calculations the real EFB does, the time it takes to input the needed data really isn't more than two or three minutes. (Once for take off, and once or maybe twice for landing, depending on some extra factors.)

The "extremely time consuming" doesn't exist in the cockpit, that's all part of the planning phase, which is not handled by an EFB.

If you take a look at the perf. calculations the real EFB does, the time it takes to input the needed data really isn't more than two or three minutes. (Once for take off, and once or maybe twice for landing, depending on some extra factors.)

The "extremely time consuming" doesn't exist in the cockpit, that's all part of the planning phase, which is not handled by an EFB.

I'm not talking about time consuming on the end users side, I'm talking about time consuming for the developer who has to create the entire backend and calculations to be as accurate as possible.

In comparison to other stuff they have done (and are still doing), I hardly think this is going to be a real challenge, or that time consuming for them.

I might be wrong, of course, but I don't think the calculation or implementation would be that difficult. In essence, all the performance part does is look up values within a table, restricted by parameters. It's not any different than what you would do as a pilot without EFB, just easier.