I am sure you are right. This was an official Scott trailer with a mechanic preparing the bikes for the demo rides and he seem to be very knowledgeable. After the ride, I told him about it and he gave me a knowing look, like he already knew this was an issue with the shifter and that was sort of how it was. He thanked me and said he would look it over.
It is a great idea and must be great on road and gravel bikes, but maybe it needs a little time to become refined on XC mtbs. Or, one gets used to its quirks like everything else and it often becomes a non-issue.
