Using 100x40mm as format I actually seem to be able to move all components top-side and still add caps on board. I am not sure about density around MCU yet, but this is one driver. The weak links are as always the current paths, but I think this will be ok for 15-25A. This is just a routing experiment and this will be ok under the assumption that I do not need a heat-sink. I do however have the option to replace the big red lane with a 1 or 2 mm wire and use hole though to bottom lane to vent the SOP Advance. In which case I can even mount heat-sink on bottom. All components on top means I can use bottom lane as ground plane as well. Lets see.
This is 25% larger than the same channel with components on 2 sides. I have several times been surprised of how little extra space I need to make components on one side only.
Also I realize how little extra that is needed to target 50A here, but lets see how we go on MCU area first.