I think you could also argue that a force user that is trying to maintain a balance between light and dark would not stay neutral. A grey force user, to me, seems more like ANH-era Han Solo, but with a lightsaber and force powers. I can see someone like that being guided somewhat by their emotions, and not afraid to get involved in a conflict if they’re angered by some injustice.
The problem that arises for me, is that this again doesn’t seem that dissimilar from a regular Jedi, just maybe a bit more self serving. We’re told from dialogue throughout all 9 movies that once you start embracing the dark side, it corrupts you. So even if someone believes they can maintain a balance between light and dark, I feel like they will still wind up being corrupted, based on the logic within the Star Wars films. The dark side is defined as embracing anger, hatred, and lust for power. I don’t really see why someone should try to incorporate those emotions into their life if they are seeking balance. I don’t see any evidence that TLJ or TROS are advocating a “middle path.” Luke says the Jedi need to end, but then later says he was wrong.
I think a lot of people are misinterpreting the dark side as simply being emotions, and that embracing the light side necessitates suppression of all emotions.