The first is definitely a "tilt doesn't lose game" fix. The second is a free play hack - when the play meter pulses, W fires, credit unit subtracts 1 and adds some number of games depending on the 2nd chute adj. Not sure what happens if up and down coils fire together...
The additional relay and wiring looks like an initial [aborted] attempt at one of the changes above -or- the beginnings of his next feature!
Edit - Just looked at the timing with 2nd chute adj on 2, the credit down fires on Motor 2C and credit up on the 4th Motor 1A pulse.
