Hello, apologies for the delayed response on this post.
Active cell balancing is typically done during the charging phase where energy can be transferred from stronger to weaker cells to ensure cells have a balanced SoC, so there would be no need to turn charging off for any reason.
Balancing while charging helps ensure that all cells are being fully utilized. Not only is overall runtime maximized, but this also minimizes charge and discharge cycles, which increases battery lifetime and reliability.