wondering if there is a way to do a bulk update of supported commodities on a car so that when I add additional cars to a consist they have the new commodity, or is there a way to copy the car in surveyor with the update?
Once you have configured the load in a car, both the allowed commodities and the commodity currently loaded (and its level), you can then copy that to all the other identical cars in the same consist.
See the Trainz Wiki at How_to_Use_S20_Palettes#Managing_Consists and in particular scroll down to the section headed Loading Consists in Surveyor (Incl Locomotives). At the very end of that section, Step
, is an icon
which copies the commodity settings from the current open car to all the identical cars in the same consist. Note that there are two of these icons. The bottom one, in the Approved Products list, will only copy the set approved products to the other cars and not the current load. The top one will copy the currently set load and its level. If you have only changed the current load from the approved list and not changed any of the allowed products/commodities then you only need to click the top icon.