I made it more complicated than it has to be. It could work really well also without the Missions.
Like in the example from Layout Templates, you could use a process just after the “FromConveyor” with a TransportPatternIn statement to stack the products before the TransportOut. The FromConveyor and this process need to be linked with an “InterpolatingTransport” and not the “ConveyorTransport” as the implementer.
Then instead of using Missions to make the Resource wait in front of the process, you can use the ReserveResource method and a “Work” statement before the TransportPatternIn, so that the resource comes and waits.
You could use the TransportPatternIn helper to make the number of products transported more flexible.