I think I fixed the errors in the spreadsheet. New version (rev3) is on the website.

It seems to work well in the simulator.

You need to check that it's not giving you negative values in the Calc. Load column on the Table Values sheet.

I'll try to make it a little more user friendly in the future.

I should probably figure out better ways to make sure the settings are right.

One thing to point out is that if your hall sensor is at 30 deg, you can't have a 30 deg advance setting!
There needs to be at least 43 uS of delay after the sensor input before the processor can fire the spark.