Much appreciated
I was able to get something like that working. It creates a high score entry in the db for each song, for each style, and for each difficulty for each 'slot' (world #1, area #1, machine #1) and gets updated when you get a higher score.
World #1 is just the highest record score overall.
Area #1 is based on the locationid asphyxia provided, meaning we have no way of changing "areas" (that I know of) right now.
Machine #1 is based on locationid and pcbid so at least we can have different hiscore entries for different pcbids.
Then all those high scores are loaded through playdata_3.rivaldata_load. Seems to work for me just fine, but let me know if anyone's having issues.