High omega for isolated particles

Hello everyone,
This post is to follow up with a problem of "isolated particles" (particles having no contacts with other particles) having such a high and unreasonable omega, especially around the base of the pile. This problem was mentioned a few years ago in this thread: https://www.cfdem.com/forums/constant-high-omega-few-particles-close-bas....
I just wonder:
1) Does anyone know how to fix or work around this problem? Any ideas are highly appreciated.
2) I was thinking of a quick solution that in my processing step using Matlab, can I reasonably make an assumption to discard particles (around 100 particles per 7000 particles inserted) if they have the angular velocity larger than 2 rad/s?
Please kindly let me know if you have any ideas.
Thanks so much.
Thao