Yes the 5300 has low read noise so you can have a low iso and not worry too much which is good for higher dynamic range.
https://youtu.be/U5d7tuYWnU0?t=333
I think the image is quite fine for a dslr but I know what you mean.
if you want to share your data and calibration frames i/or someone else here could take a quick look at it.
cheers