SK450 extended leg with rod hole and reinforced

This is a remix of the SK450 extended legs with a hole added for the two rods used as bumpers and for maintaining orientation.
Version 2 is a reinforced version to handle the stress I've seen cause breakage on my earlier model.
Version 3 elongates the leg a little bit and uses a rounded bottom.
3.5 thins the leg by 1mm to avoid the need for some sanding after printing. The added reinforcements more than compensate.
V4 is a little heavier but is intended to provide further reinforcement.