Nintendo Switch Con U v2 (for 0.5mm nozzle)

I increased each rail thickness by 0.1mm in Meshmixer.

In the model's original form, my slicer wouldn't pick up the rail as a feature at all for my 0.5mm nozzle. My first print came out with no joy-con rails.

It was a little snug sliding on an off, but that might be more an issue with my printer getting on in age and needing more fine-tuning and nozzle maintenance. YMMV