Thanks for taking the time to identify what info is important for your response.
here is my input:
1. I run a home layout with 5 grandsons ,ages 5-15. They are careful but make mistakes.
2. I have 5 circuits I wish to protect
3.I use two Lionel ZWs and 1034 to power my layout.
4.I run MTH DCS with 1 TIU and 2 AIUs, using handheld MTH remotes or an iPad.
5. At maximum, we run 2 engines (post war Lionel)and/or MTH ps-2 (on an inner and outer loop) , and one post war trolley circuit. These are used most of the time. But I also have two circuits and two separate tracks that run off Momentary push buttons for fire car and a gang car.
Hope this helps and thanks for your thoughts.
Jack