Do you need to start or finish the game before the XP boost applies?

Mess Room
1

Feels like the game needs to end while the booster is active for it to apply?
Which sucks when you have 25 minutes left of the booster and your game lasts for 26.

2

Any booster counts as used once as soon as a match starts when it’s active.

The duration of said match is irrelevant, and the booster will apply to the final score.

3

If you start match with booster On, it get all of it.

4

That’s good to know, thanks.
Now I can start looking for new matches with 3 minutes left on the booster.