A remix of dtphantom's design.

I rebuilt the model keeping just the external and charger cutout dimensions.

I redid the cable channel from scratch, now being centred in the wall and following a smooth path all the way from charger to cable exit.

All the edges except those touching the print bed are radiused to avoid sharp corners.

It should be fine to print without supports, I flared the inner edge of the cable exit point so there is less bridging when printing. Wall thicknesses are minimum 1.2mm, so should work well with 0.4mm and 0.6mm nozzles.

I've uploaded the full F3D file so you can see how I did it.