Definitely. There is always a gap, sort of, in time travel fiction. Like how does the characters figure out which place or point in time do they want to land exactly and not fall into an alternate timeline by mistake. In Tenet, it's simply rewind to the point and play again but without the turnstiles (checkpoints) to exit back, it will be a hell for whoever enters the inverse world. The machines need to exist for inversion, imagine you went past the creation of the machines. No exit.