Yes you'd use multi-step mode for your example. You'd have step 1 do 225 until the food probe gets to 200, then step 2 would be 160 for some long period of time (or until the food probe hits something impossibly high). If you wanted it to keep at 160 for say 2 hours and then turn off, put a 2 hour timer on step 2 and then have no 0 degrees with no time limit in all subsequent steps.
In my case I typically just cook with a single step so I disable multi step mode and the smoker will just turn off once the target time or temp is reached. The smoker is well insulated and retains heat really well for hours, even in cool weather, so I'm not too concerned about keeping it warm inside. Plus I'm usually around to yank the meat out and throw it in a cooler with towels or whatever as soon as it's done. But I do see the value in multi-step if you're not going to be home when it finishes.
Turn the power off and unplug the smoker when not using it. Your settings are stored in the smoker regardless of power, so when you turn it back on again it will fire up the last cook profile you used. Just connect the app and adjust after you turn it on. You have plenty of time to get it configured while it heats up.