What determines what works with Barrage?

The description states "Ready a volley of arrows, empowering your next bow attack to repeat multiple times. Consumes frenzy charges on use to add additional repeats." This is reinforced by the text, which also indicates it empowers your next bow attack to repeat 2 times plus one per frenzy charge consumed.

So, given that, I would expect that things like Voltaic Mark and Sniper's Mark wouldn't work, being spells, and things like Arrow Rain and Vine Arrow should technically repeat but uselessly (since only one rain of arrows can exist, and while multiple vine arrows can exist if they cover the same area it's max 1 affecting a given enemy)

Other than that, every skill in the bow tree is tagged with bow, and is an attack. So they all should work, right? But they don't. Snipe is a channeled attack with a variable attack time, but it repeats fine. Toxic Growth on the other hand doesn't work at all. I'm just trying to figure out, is that a bug? *Should* the rest of them all work with Barrage, and it's just buggy since it's EA? Or am I missing some limitation on what skills should be compatible based on the description and mechanics?