I don't think using the chart as-is would be advisable, as that would probably scale AC far too high to stay within the +11 cap (+5 attribute bonus, +6 proficiency bonus), especially considering classes that augment AC with other attributes when wearing light armor or no armor.
A variant using half your proficiency bonus (as kerleth stated) would likely work just better. Or, if you prefer, figure out the maximum bonus you want to apply based on how high someone would have to roll to hit (don't forget to consider attribute and proficiency bonuses) then work it out fromt here.