Yes to both.
To run postwar you need to vary the voltage to the track, two ways to do it. One, by using the TR button not the ENG button. You will assign a block a TR number, then you will address that section. The other way is to just adjust the voltage on the transformer, if less voltage goes into the TIU, less will go to the tracks.
For the LC engines, just use the remote or the app, set the track voltage to 18.