What tells you the hub has a 40mm chainline? It should be 42mm. Did you measure it? If you measured it do you have some janky chain tensioner between the locknut and the frame adding a couple mils to your measurement? You could buy a BB with a 103mm spindle, which is what F5 apparently recommends anyway:
Originally Posted by fancy crank mfg.
On a standard 68mm bottom bracket shell, a 103mm BB will give a 42mm chainline, 107mm for 44mm.