Yeah, but that’s not due to potency. Hit’s Time powers come from his ability to essentially create his own pocket of stored time. Him using it in a Timeless Void, for example, would work be due to the fact he’s bringing Time with him to begin with. That said, there would probably be no time for him to accumulate in his Dimension when used there. (Though, obviously, Hit wouldn’t be able to use his powers due to being unable to move. This is just a hypothetical.)
Similarly, Whis outright says he can (and story straight implies he does) travel through time WITHOUT the aid of a Time Machine. Meaning Whis’ travel and/or control over time isn’t bounded by the current one he is in. This makes sense, considering the Grand Priest MADE Time in the WoV for people to experience.