Something to consider is the complexity of proposed options.
The pairing process already takes a lot of time, to the point where we've had to shift the schedule to 2 games per day.
This is just plain wrong. We switched to 2 games per day to get more time for the social part (beers and so on). We started at 10:30...
We can easily fit a 3rd game per day if we really want to.
I think that the pairing process will take the same amount of time with selection of the objective or without. There is the same number of steps, the number of options from which to select is a bit bigger but on the other hand one can have a similar strategy (no rotation of the objectives depending on the round) every round.
Adding another level of complexity won't help. If you ask me, I'd rather get more games in (say, 8 instead of 6) if possible.
I like the idea of a "game inside a game" as much as the next person, but this is becoming ridiculous.
As an ETC player (and with no concertation with the rest of the Belgian team) I believe that randomly determined scenarios and deployment types is the most straightforward way to do this. It is also the best way to test the mettle of the would-be top players of the world. See if they can devise a list that can play any scenario and deployment, against any opponent.
Go play ESC. Team event is about team strategy.
It's so easy and quick, too. You do the pairings like last year, only in the end you randomize tables. Then, you roll a d6 two times per match: first is deployment type, second is secondary objective. No need for veto rules or objective cards. The game is complex as it is, lets not make it more so.
My 2 cents