Well, I've identified the cause of the problem.
The script that assigns which ability score to use with finesse weapons looks like this:
Code:
doneif (field[usrChosen1].ischosen = 0)
perform field[usrChosen1].chosen.pulltags[MelAttOver.?]
foreach pick in hero from BaseWep where "wCategory.Melee & (wClass.Light | Helper.Finesse)"
perform eachpick.pushtags[MelAttOver.?]
nexteach
The culprit is the foreach line, I believe. Kinetic Blade and Kinetic Whip do not appear in the list of items to evaluate because they lack the tag Component.BaseWep.
Obviously the regular Weapon Finesse feat is applying to them correctly, so I thought I'd go look at its code. The feat itself just assigns Hero.Finesse, which presumably triggers a script someplace else. I'll be jiggered if I could locate that script, though. I spent ages poking around in Procedures looking for it. It might be hard-coded into HL.
I'll keep poking at it. Maybe if I add a second foreach loop targeting BaseEquip? They've got that tag.