Are you saying if one adds a stop next to the planned stop, the car will not turn on pre-condition?
"Nearby", yes. Although nearby can be very close - elsewhere at the same motorway services, for example
How else can one prevent pre-conditioning from happening?
When it comes on there is "click to cancel", but not sure how you would then turn it back on (other than deselect / re-select the Supercharger in Satnav)
But isn't pre-conditioning good and recommended before a long stop?
Yes (more to make the stop shorter, not
per se for a long stop), but recently (OTA update) it has been coming on very early in the leg. That means is uses up energy heating the battery ... and that energy loss might restrict your choices (in particular in heavy traffic / slow driving / increased range which, absent the pre-conditioning, could have enabled you to reach a further charger). Personally I don't want it to come on until I am about 50 miles away.
But you don't need to get embroiled in any of that, unless you want to. I'm a geek and not everyone else is!
What happens to the charging process if it does not take place?
Charging would take a bit longer. The aim is to get the battery to ideal temperature for charging, so that charging is as fast as possible.
If you are stopping for lunch you would be better off cancelling pre-conditioning - otherwise the car will be charged and ready to go before you've finished your Hors d'oeuvres!
And, actually, if stopping for lunch NOT pre-conditioning will save you some money. Preconditioning uses energy to heat the battery, which you then replenish when you charge (but, overall, the charging stop is shorter .. but a bit more expensive)