Best mods imho (just a few ones from a technical point of view):
- tieback diodes on coils instead of tieback wire (the 4 connected to the aux driver)
- LED flashers inside the borgship (prevents melting borgship when playing a lot of MB)
- Pullup/pulldown resistors on the data and clk of the aux driver (prevents locked on coils by old flatcables)

See https://pinside.com/pinball/forum/topic/sttng-locked-on-divertor-coils
Last post shows the resistors

The tiebackdiodes is easy: just solder a diode on the coil itself. Sometimes when the wire is broken the voltage spike is not fed to the 50V supply, but with a diode on the coil itself you don't need this (kinda flimsy) wire.

The banded side of the diode goes to the 50V. That's the thick wire which is daisy chained to other coils.

Yes, I mean the coils of the top droptarget, there's an d.t.-up-coil, and a d.t.-down coil. Both are controlled from the aux driver.
1N4001 is NOT a good type, since the reverse voltage of the diode is 35V, and its a 50V circuit. I recommend 1N4007. I have also used 1N4004, which is also ok.

By doing so the thin lavender wire is useless and can break/fail without causing damage.