Well that's an... unfortunate oversight on my part. Annoyingly I can't really update this or any other mod of mine, since I recently moved to Linux. Playing and modding the game is one thing, but alternative mod uploader doesn't want to play nice judging by a few quick attempts.
Maybe if I ever have a moment to dig out my laptop and still remember by then, but for now it'll have to remain as it is, sadly.
But thanks for letting me know all the same.

Hey! Cool class, but I noticed I couldn't unequip my secondary weapon and after looking it up in the original stormrider class mod I found you hadn't added the "empty" weapon as allowed secondary weapon for the stormcharger spec. Couldn't use the second part of that stormrider passive that gives a move on all melee attacks when secondary weapon is empty.

I added in myself, but figured I'D let you know in any case.

It might work with old Primary Secondaries, but I haven't tried that. I'd still recomend True Primary Secondaries regardless, found it less problematic overall (at least when used with Iridar's fix for Musashi's mods), and near as I remember things that require old PS should work with TPS by default.

does this only work with True Primary Secondaries and not regular Primary Secondaries?

Not all, but large enough amount. Made it incompatible with heavy weapons with exception of gauntlet, other melee specs, and other psi-themed specs. And Phoenix and your Geomancer since those want to be paired with specific primary specs.

Nice work. Is it allowed with all other specs?