You could crack injector lines to see what cylinder is giving you all the white smoke. Maybe borrowing a known good compression tester would help. A borescope shoved in through an open intake valve is the only other time saver I can think of. If you see valve dents in the piston the valve(s) are bent period.
At this point the head really needs to come off because other than the valve locking up in the guide - it ate something. Locked up valve also needs head off service. An inspection of the turbo - BOTH WHEELS is in order as debris can/will bounce back into the intake and migrate to other cylinders.
At this point the head really needs to come off because other than the valve locking up in the guide - it ate something. Locked up valve also needs head off service. An inspection of the turbo - BOTH WHEELS is in order as debris can/will bounce back into the intake and migrate to other cylinders.