I just realized that 3D Space Pinball (or Space Cadet as people know it) that came installed with Windows has a higher quality version called Full Tilt, which has slightly different rules and much higher definition board. It can be found on: https://archive.org/details/full_tilt_pinball

And most importantly this version works with the open source version: https://github.com/k4zmu2a/SpaceCadetPinball

I played few rounds and managed to better my old high score quite a lot, but like I said the board rules are slightly different so the scores aren't directly comparable. My new high score is 7985250, but this was just done in couple runs so I should be able to get a much higher one.