@the fickle finger
Your wish for more speed ("40 kts more") would be getting you well into the "Sonic Cruiser" area - and Boeing found no takers, remember ?
There are lots of possible ways to reduce drag, as you will no doubt know, but all have weight, cost, maintenance and other disadvantages, so designers have to come up with the best average ....
Not that that makes long flights any less booooooringggg, I agree !