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@gbj_tester
Do we need the shell to be more than 68mm wide? Anybody concerned about Q-factor, ankle clearance and aerodynamics will surely go for BB30, which already provides plenty of shell width for attaching the other tubes, along with a slight increase in shell diameter to allow deeper (but not wider) down tube and chainstays. BB386 just moves the bearings back to where they are with external cups, with the corresponding long axle and tight space between the bearings and your ankle bones into which they have to squeeze a thin crank.
FSA are touting the 30mm axle as some kind of revolution, but as Zipp has shown, the 1.370"x68mm shell can already accommodate that. The good thing about BB30 was not the (non-existent) increase in axle diameter, but the return of the bearings to a 68mm spacing making more room for the crank. As any fule kno, cranks are usually fine if you get the torsional stiffness about the long axis right; everything else looks after itself. As a first approximation, the torsional stiffness of a non-circular beam is barely more than the torsional stiffness of a circular beam which will fit inside it, so making space for the crank to be thicker from side to side without reducing ankle clearance or increasing Q-factor was a genuine advance introduced with BB30 compared with external bearing designs on 1.370"x68mm shells. BB386 throws this away merely for the logistical convenience of crank manufacturers, who now only need to make one axle to rule them all.
Given that this is the only reason for the introduction of this spurious standard, it's no surprise that it comes from the manufacturer with the greatest exposure to the OEM crank market, FSA. Their whole business is founded on creating an illusion of value by pricing their aftermarket components, and especially cranks, at least 100% above what they are actually worth next to other manufacturers' offerings, and then selling them at their true worth to OEMs as substitutes for the main groupset manufacturer's crank.