Branching Bolts - Does not apply to Arc?

Hello,

Just a quick question, I've allocated skill points into the following three talents in the skill tree:

- Lightning Skill Chain Chance (20% chance for Lightning Skills to Chain an additional time)
- Lightning Skill Chain Chance (20% chance for Lightning Skills to Chain an additional time)
- Branching Bolts (60% chance for Lightning Skills to Chain an additional time)

However, unlike many other Lightning-based talents in the skill tree, for the ones mentioned above, when I hover over the nodes and hold Shift to see the compatibilities, my equipped Arc skill is NOT listed.

This seems a bit bizarre to me, as it feels like a natural extension of what Arc already does?

Do these nodes actually NOT have any effect on the Arc skill? or does the Shift+hover tooltip just not show this one?

Thank you!