The biggest limitation here is not Photoshop—it’s the sky quality. Being only a few miles from a large city means there’s significant light pollution well above the horizon, so much of the Milky Way’s faint detail is being lost before processing even starts. A darker location will make a far bigger difference than aggressive editing.

For processing, focus on standard Milky Way workflow: carefully set white balance, increase contrast, deepen blacks, and use selective clarity/dehaze-style adjustments to separate the Milky Way from the background sky. You can also reduce the orange cast in the foreground with local color correction. But with strong city glow, there’s only so much recoverable detail in the RAW file.

So yes: a higher ISO may help your capture, but the main improvement will come from shooting under darker skies and then applying typical Milky Way post-processing techniques more selectively.