To build out from the back, that's where Jack should be. IMO.
I thought Tavernier was ineffective in his end-product, but not in his positioning; he was isolated, one-on-one, against that left-back time and time again, which is what we should be doing, IMO.
I do agree that Jack can move further forward to aid in the attack and ball-recycling -- that was arguably our biggest success last night, at least in the first half: Aribo, Jack and Davis occupying the half-space to aid control, ball-recovery and keeping the pressure on; while also getting into dangerous areas.