<R20> Are we allowed to make non-electrical modifications to the motor, such as what is shown above? When the cap is modified, "cart-less" motors will have less friction, as they wobble due to a lack of preciseness. Many motors on flywheels are also very likely to overheat, so the removal of the shell would reduce overheating. Can the posts of the cap also be shaven down in order to reduce motor stack height?
Non-electric Motor Components
Rule <R20c> provides an inclusive list of competition-legal modifications to the V5 Smart Motor, and Q&A 1189 clarifies that shafts may be connected to internal components of the motor with legal parts other than standard cartridges.
The modifications described and pictured in your question are not permitted in the Spin Up competition.