Thanks for playing!
The seed system was put in early in development when it seemed like the focus of the game would be getting high scores on particular seeds and competing against friends etc, but I ended up pivoting away from that direction. I agree with you that the feature is pretty vestigial now.
Also, having run-to-run progress would definitely be cool and fits well with the 'get better and better scores to unlock more achievements/ribbons' meta game that the project settled on.