I just discovered a hole in the higher education implementation in trying to help freakacid with his questions. It appears to be impossible to select a second "Advanced" field, which is explicitly permitted on page 70 (the third bullet under "Master Schools List"):
The player may not choose more than three Fields in total for a school. (Choosing a second Advanced Field is a viable option for a third Field, as is selecting a Special Training Field.)
Also, on the Attribute Selection sheet there's a spelling error: "Flexible" is incorrectly spelled "Flexable" in both the "Choice/Flexible XP" block and the footnote for that block. I also see it's misspelled on the Attribute sheets. I recommend doing a global find and replace throughout the workbook.
Working through this, I see one critical difference between our spreadsheets. I tried to program mine to do optimization automatically where yours is manual. Granted, I'm assuming all the Flex requirements are simply met during optimization (my rationale being that with all those points sloshing around, they're bound to be met), where yours explicitly lists them as reminders for the user the to meet.
If you PM me your e-mail address, I'll send you my current version (which I'll eventually post if I get it fully functioning). I'm not an interface guy, so it's pretty ugly. Calan (another poster several years back) gave me some more elegant formulas to use, but I haven't quite wrapped my head around them, so they're only where he put them in.