The logic behind the removal of the fan is simple. Most people just tape the holes shut, to keep the crud out.

With the powerlevels we use the motor on, the rpm of the motor is low, so the fan doesn't add a lot of cooling.
In the past we have seen motor failures due a fan that got pretzeld and started chewing rotorwires.
The fan is steel, so it's a few grams that you can gain without any loss.

If you keep it on 24V (or 6S), then you can get away with a "lower level of ruggedizing".
Weld the front plate , and use a load of Araldite to give the magnets more support.