I just ran a large Lionel Thomas and Circus theme display for 2 full days at our local train show.
We let the little kids 2-100 year olds but mostly the small ones handed them the Lion Chief remotes for Percy, James and Thomas and let them run the trains they loved it and was easy and great way for them to run trains without being in the layout area or touching transformers.
To keep them from going to fast we set transformer volts to these loops of track low enough to keep the engines (at full Lion Chief throttle setting from going to fast)
However the Lionel Chief + has one feature that would not be good for the kids and that is the coupler release!
I could not use one of these engines as the kids would trip the rear coupler release and dump the train to create all sorts of problems!
Perhaps Lionel might consider a switch to turn off the coupler opening feature. If the kids hit the Whistle button it is bound to come open!
Otherwise sounds great.
We now run all three Lionel Chief engines on the big layout with DCS and TMCC on at the same time and they work well.
Only problem is that they controls are really slow to respond to speed setting so really easy to fly right past where you are trying to stop.