Well, I asked and as a result it was clarified by author to only scale with incanter level at least.

In other classes though, I feel like the power of Hedgewitch 2 as a dip is probably being underestimated here as you don't even seem to mention it? Hedgewitch 2 seems like it'd be easily green, and there's an argument for blue. Purple would be stretching it a bit much due to the loss of CL, but it's way better as a dip than Hedgewitch 1.

This is because Hedgewitch Secrets are pretty easily the best class talents in both base Pathfinder and spheres, but you don't get it till Hedgewitch 2. Add in the class items which grant you an extra secret and path benefit, and that Extra Secret can be taken any number of times, and a hedgewitch 2 dip can be a significant help for a lot of builds. Like, there's a secret which gives you a hex and hexes were purple, but you can also get rogue talents, ninja tricks, alchemist discoveries, arcane discoveries, revelations from the heavens, lunar, and solar mysteries, shaman hexes as well as the aforementioned witch hexes, magus arcanas, first level domain powers, investigator talents, versatile performances, 1st level eliciter emotions, and mystic combats. Plus you know, the actual secrets themselves.

Although to be fair, you can only get one each of arcane discoveries, mystic combats, and oracle revelations, but the best are really limited only be the amount of secrets you're willing to throw at it. The sheer amount of options mean any build that can eat the -1 CL can probably benefit though, as that's easily hundreds of options.

That and the aforementioned incanter issue, in that if you take a sphere specialization you don't get your other specializations until level 3, as they fairly justifiably nerfed how dippable it was in Ultimate.