Burger, in-person match - that's fine, but the early or late time of the game shouldn't affect the outcome. At a minimum, there should be a rematch (blitz at 200%, for example, in Might & Magic). With equal results, you should never resort to such unfair tactics, if only because these scenarios (draws) are calculated in advance, and it's therefore not difficult to calculate your time, etc. You could, for example, play a fun game with a teammate, and that game would count as a tiebreaker in case of a draw.
Moreover, if this is announced in advance, no one will argue, because everything is recorded according to the rules! And the outcome will remain legitimate.
I wrote this here because the OFB (Online Fighting Battle) is considered a qualifier, and no other tournaments are comparable in principle for participation in the FB (Fighting Battle), and therefore such a principled approach to participants in the FB should be accompanied by an equally principled and correct approach... You need to select players based on their strength (results), and not on anything else.