I only see one purpose for having a time limit in H3 and that is to avoid wasting (your opponents) time. H3 is not a real time game. Therefore I dont believe you get an unfair advantage by loading a game in single player to look at your situation as long as you only look and dont play on. You should be able to think things through as much as you want as long as you are not wasting your opponents time, which is not the case if you load the game in single player.
Luckily we can avoid this issue in the future since we can now play with protected saves, where it is not possible to load the game in single player.