Beyond reach quiver not adding chaos damage to some attacks

The added chaos damage from the beyond reach quiver seems to only apply to attacks that fire and hit with an actual arrow. As in basic attack, rain of arrows, the first portion of stormcaller arrow, but not the lightning bolt of the same attack.

Electrocute and freeze buildup with chaos seems to work fine, as far as I can tell.

Tests were done both on tooltip and with attacks supported by withering touch, with and without purple flames active. Tooltip shows exactly what is described above and the wither stacks were also applied following the above logic.

Always with quiver and withering touch support on, no other sources of chaos damage:

Stormcaller arrow - first portion
always applies wither

Stormcaller arrow - lightning bolt portion
applies wither only with other sources of chaos (here purple flame), but not with quiver only

P.s. not sure whether this is the same with the other two unique quivers as they also add extra damage on a quiver base, just not chaos.