Hi,
Well, to maintain the optimal performance, the "automatic rebuilding" of the RC object is triggered just on some 3ds max events when using the Extend X/Y Size to Area mode. Using the Display/Build > Build button should do the trick. Optionally, you can disable&enable the „auto-update” option by:
$.autoUpdate = off;
$.autoUpdate = on;
I hope that helps.
Best regards,