Summary: explosion damage multiplier reduction from a single segment can/will effectively zero out all damage to all other segments in the explosion (rather than impacting just the immediately simultaneous ones). Testing from Swoosh and MrGimp have confirmed the problem behavior, and code examination by myself and Eyeballin'have also informed this report.

Background: as designed, enemies taking damage in an explosion segment will decrease a damage multiplier for that segment, as well as (to a somewhat lesser extent) decreasing the damage multiplier of the two adjacent segments. A single segment has an effective limit of about 4-5 enemies before that segment's multiplier will cause zero damage applied thereafter for going less than 5%.

The Problem: the multiplier impact is "traveling" further than it should, and is especially noticeable as it gets closer to zero. Damage reduction originating from one segment should stop at the immediate adjacent slices.

Suggested solution option 1: split each segment's damage reduction multiplier into two distinct multipliers. One for the component applied by enemies within the segment itself, and one for "adjacency reductions" applied by the immediately adjacent segments. Both would be used in the damage calculation for enemies in that segment, but only the in-segment multiplier would be applied to adjacent segments' "adjacent reduction" multiplier.

Suggested solution option 2: remove the reduction to adjacent segments entirely.

In either case, such a fix (acting s a buff rather than a "nerf"), could be implemented in the current season with no detrimental effects to the top scores possible in leaderboards.