I mean they don't need to be equally available, just that there should be strategies that make any singular one of them easy in the late game (they can even still be mutually exclusive, it's just that ).
you could also just make it an accessibility feature in the settings, since probably 60-80% of people would find the time goal to be just right, and that it would be too easy for such people if you lowered it (it would be an honor-type system though, in terms of people not using it when they don't need it, but I think people would respect it, kinda like assist mode giving you extra life in Mario odessy)
timing is a notoriously hard thing to adjust for, because you don't know how long people will take on each step while thinking about things, especially on as short of a timescale you have here. The times it does work are usually when a predictable, repreatable interation is initated by the player, allowing them to take the time they need to adjust to it.