This turned up in my YouTube recommended about an hour ago... a couple of hours ago*
Most of this is only really relevant to dedicated Lego operators, but I recalled talk on this thread about building O-gauge compatible powered units. Round about 6:24 in the above is something that may be of interest.
Being that that aspect of the above project is in development, it might be possible to ask if there is a possibility of an O-Gauge compatible variant (most likely in the form of 'O' compatible wheel/axle sets) being added to their motorized bogie project. It could potentially be useful to more than just Lego-derived trains.
---PCJ