Would it be possible to integrate a 68 position PLCC socket into the design?
Like this one:https://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/8468-21B1-RK-TR/?qs=sGAEpiMZZMs6akeJfFiy2rc%2ftN2YUFFe
This would make the mod infinitely easier, just snap on and solder wires to the output connector. The NeoBIOSMasta (https://www.neogeofanclub.com/projects/neobiosmasta-og) uses this technique.
Edit: Though this may not be possible due to components too close to the IC.