Yorkshire Dave
Western Thunderer
When do we start panicking, again?
You don't - I wouldn't even bother to start worrying about panicking.
You just need to make sure the layout wiring and operation of is reliable. The trains will then flawlessly and no-one will notice.
When assisting friends with a large Austrian HO layout we used to set it up, run a test train in either direction then retire to the pub* (if setting up the night before)......... ready for the invading unwashed rucksacked hoards the following day.
* but not the same one as the other layouts operators .....