Good find RoundMound. I'm not as into the "success factor" because I wouldn't want them to punish any school for success. It would be nice to see the participation rates from the Iowa private schools vs. Public schools and use that to find a proper multiplier/reverse multiplier number.
I understand that thought, but I think what you find is that the schools that have sustained excellence (or domination if you will) have inherited advantages similar to private schools and their built in advantages. Besides, to move up a class you would have to either make the state finals two years in a row, or win the state championship and make the semi-finals in consecutive years. If your program is that good, you should move up a class to try your hand at some better competition.
For kicks, here is the list of schools since 2007 that would have moved up a class for 2 years if using the Indiana model. The year given is the year prior to move up, so "2015" means they would move up next year.
Football (didn't count 8-man)
Central Lyon - 2008 2A to 3A
Decorah - 2012 3A to 4A
Gladbrook-Reinbeck - 2015 A to 1A
Heelan - 2008 and 2013 3A to 4A
Kuemper - 2013 2A to 3A
North Fayette - 2015 2A to 3A
North Tama - 2010 A to 1A
Pella - 2015 3A to 4A
Regina - 2011 2A to 3A
Solon - 2007 2A to 3A
Southern Cal - 2008 A to 1A
Spirit Lake - 2012 2A to 3A
St. Albert's - 2007 1A to 2A
West Lyon - 2014 1A to 2A
Basketball
Boyden-Hull - 2013 1A to 2A
Danville - 2010 1A to 2A
Heelan - 2010 3A to 4A
Mt. Pleasant - 2012 3A to 4A
NU High - 2009 1A to 2A
Rock Valley - 2010 1A to 2A
Solon - 2009 2A to 3A
St. Mary's - 2012 1A to 2A
Wahlert - 2015 3A to 4A
Waverly - 2014 3A to 4A
West Fork - 2014 2A to 3A
Western Christian - 2009 2A to 3A