I understand the concern. As a regular practice, on raceway systems, I group the neutral with its related phase legs and use a wire tie or, at minimum, tape to identify the group, close to the raceway entry to the panel (assuming more than one neutral is in the raceway). If I have to verify neutral - phase leg combinations on an existing panel as part of the changes I'm doing, again, I'll mark the multiwire group with wire tie, etc., so as not to have to duplicate my effort the next time.
Al
