Yes, there are a couple of things you can do to deal with the gradient. You can expect good results with time and practice. First off, nice job collecting pinpoint data. looks like you even caught a satellite zipping through Orion.
The easiest way to deal with light pollution is to deal with it before it reaches your sensor. Astronomik makes clip-in light pollution filters designed to use with your mirror-less camera. They make a a variety of filters but you need to be sure that the one you select will work with your modified camera. I think you had mentioned that your camera was modified to full spectrum in which case you will need to buy the CLS CCD clip on filter. They are usually a little more expensive than the the other light pollution filters designed for unmodified cameras but you will need that specific one because it will also block the the longer wavelengths of IR light that need to be dealt with. See attached for the range of wavelengths it lets through vs the wavelengths both types of filters block.
Another method you could use is to try and deal with it in post using the various tools available. Some work better than others and at the very least require some familiarity with the software. This specific image might be a bit tricky because the trees may confuse the software, unless up want to take to time to remove them.
What time was it when you took this image? was it completely dark out yet?
You may also benefit from taking exposures when dealing with a target bathed in light pollution. Another way to help limit the light pollution is to wait until the target is highest in the sky. Since we are so far North, you don't have too many options with this guy. This is such a large target, it's not going to be easy to remove the gradient but I definitely think the image can be improved.
This a good opportunity to practice using the various tools available out there and see try improve. I don't know what software you prefer -- there are a multitude of instructional videos on you YouTube. That might be a good place to start. If you have any more questions, feel free to post your results here perhaps we can dedicate a future workshop on how to deal with this problem.