I could use some help with custom firmware

I have an Ender 3 pro that I am trying to get set up with a Bondtech DDX and a Slice engineering Mosquito Hotend. The printer has the 4.2.7 board and a CR touch sensor. According to the documentation I need to change the sensor to the slice 100K thermister, which I found in the custom firmware builder. According to this documentation I also need to change the e-steps for the extruder motor, I could not seem to figure out a way to do that with the firmware configurator. Is it possible or am I missing something? Using G-code after the fact seems clumsy after I have taken the step of loading a “custom” firmware. Can we add the BondTech DDX to the extruders in the configurator?

Also, I am wondering what options are supported by my printer, there seems to be a few options in the leveling options menu that say “if supported” I have the stock LCD that came with the Ender 3 Pro, are those commands only supported on the V2?

It looks like someone else had a less detailed post about this here: