What happens if an engine management software update is done at the car dealer? Will it erase the remapped version?

Yes in that case it will most likely erase it. During warranty phase, you cannot refuse this update without losing the warranty, but after that just stipulate not to update the engine software when you give the car to the dealer for maintenance. The good news is that it does not happen that often. We will remap the car again if you need it anyway, and this for a very low price (60 EUR) to cover the labor costs.