After some feedback on the original ship and some more personal testing I came to the conclussion that the spread of the mining array does not compensate the lag that it causes. Therefor I removed the outer layers of of salvage modules and managed to bring the total amount of groups back to 3000. It's still a bit laggy on larger asteroids, but should be much more useful now.
Sorry for the inconvenience with the original ship. As I already said, it was a bit of an experiment on how big I could go with a mining ship.