I'm going backpacking through Europe and I don't know my longest destination or my actual destinations, to be clearer.
While I can co-relate to your spirit here but one thing you should never do is not ensuring the country which issued you the visa be not your actual destination.
I am not saying you can't get away with it (I know people who luckily did manage without any trouble) but this move is risky and presents following risk:
- Possibility of being denied flight boarding
- Possibility of being denied entry at border patrol
- Possibility of being declared as risk for future visa
- Possibility of being denied future visa during your next application
That being emphasised about "main destination" (and genuineness of intent to travel, like being backpacker with legal source of money) you can modify your itinerary, purpose of visit, add more countries, increase total time till it's under conditions stated in your visa issued. The visa issued has validity, max days, valid for number of countries, valid for number of entries kind of details to keep a tolerable check about everything else.
p.s.: whenever I have been questioned the only question I have ever been asked with judgement tone at VAC, Check In Counter, Border Patrol is are you going to spend max days in the country that issued you visa.