Tax 5 with dual extruder v3 using one extruder

What is the best way to print something with one extruder on? The second extruder is on while I’m printing and I don’t want it on. Using Cura 3.6.3 on a windows pc

I’d create a dummy material with as low as possible temperatures and tell CuraLE to use that in the second extruder. There is a minimum temperature below which the Marlin firmware will not allow extrude commands. I going to guess (from the Marlin config file) that the minimum temperature is 120 but you may be able to set the standby temperature lower.

#define PREVENT_COLD_EXTRUSION
#define EXTRUDE_MINTEMP 120

You don’t have to put any filament in the second extruder but the default start code will pretend like there’s something there anyway. It is probably possible to define a “new printer” with different start code that could eliminate some of that, but I’m guessing its not worth it.