That video seems to be explicit....no gauge was used in it...just "for your eyes only." He suggested the manual suggested rotating the crank 120? but this seems to be a way to screw the pooch.
Via another vid, I saw a vacuum pot hanging off of distributor that looked Bosch-ish.
Timing advance on that V6-PRV-engine's distributor would be done by a metal plate below the rotor that would rotate with changes in vacuum from intake.
With time, the vacuum pot shoots craps, vacuum line is blocked (no vacuum to this pot), Hall sensor's wires
'Pulse generator' in this distributor... Hall Effect got used in more modern systems. All analog in this one! are not sending full current to ignition module, and/or the rotating plate is stuck in one position.
In point days, the point's wire going to coil would be broken (open circuit) inside the wire's protective sheathing, due to rotary motions of this plate. ,So, a mechanic could not see this, and the engine may run, and then quit, and then run again.
So, if a hall sensor (or whatever is there) is rotating on a plate via vacuum pot, I can't say how this would affect
this type of ignition module that was on my VW Rabbit.
Thus, vacuum pot must rotate that plate, there must be a vacuum line from intake manifold feeding it that works, and if OEM hall sensor is in distributor, it might be wise to get a new one since its wires may be somewhat broken internally.