So I decided to push my puny PC to the limits and see how many stars I could get Space Engine to show on the screen by increasing the star magnitude setting. To my surprise, I was able to get the semblance of the Milky Way whilst having the galaxy display option disabled. I had to tune and mod the game a bit to make it look decent and run acceptably. It's noteworthy that a sphere around the Solar System with a lower density of stars visibly manifests in these conditions.
This seems to be the absolute limit of my PC. If I try to go further, the galaxy will begin to flicker and slowly reload indefinitely. I suspect that systems of the highest caliber will be able to perform even better. At the very least, a monster rig should be able to pull off more than the single-digit frame rate I got. I challenge you to try the same and share the results.