ideal protein concentration?

[andrewkern]

over on #2 @joelmcg brings up the suggestion of using high gluten flours like Sir Lancelot or All Trumps, and notes

Sir Lancelot has 14.2% protein. King Arthur All-Purpose flour has 11.7%, VWG 75%. Using 1 c = 128 g: 992 g SL * 0.142 = 141 g protein 949 g AP * 0.117 + 43 g VWG * 0.75 = 143 g protein

I wonder how much higher we could push this? some of the bagels that I grew up with were like lead weights