Exo K4 experience with tall guys

[Okie84]

Are there any guys (6’7 or taller) who have experience with the 26.5” K4? My brother is 6’8 with a 36 inch inseam, so he has long legs, but he’s 6’8, so his torso’s obviously long as well. 34-35” waist, slim athletic build. He currently has a K3 pack, however, he has experienced quite a bit of slippage with it. If he could upgrade to a K4 that would be great, but I don’t know how well the pack would fit someone of his height. I am most interested to hear if the load lifting angle is adequate for someone of that height. Anyone willing to share their experiences would be greatly appreciated. Thanks!