For e.g. very long maps, or even something like piercy's strafepad map. You would have a "pause" field after each teleport. Or possibly a key at the teleporter to allow pausing until the player jumps. Pausing would mean that the timer would stop moving until the player leave the field (or jumps if using the 2nd method).
That whole having to CJ asap/get moving thing isn't particularly awesome tbh. And this could make some longer maps a lot more enjoyable.