I get paid good money to creatively rewire million dollar machines so they do things that they 'can't'. I prefer relays as anyone coming in after me should be able to see what I did, or just throw fresh relays at it, unlike with PLCs... My favourite machine has a 454 page book of wiring diagrams. One of my additions to that one consists of 6 signal relays and a switch. It effectively made the machine 6" bigger. That meant we didn't need a slightly bigger megabuck machine. Hmmm, new $1,000,000 machine or a $50 hack?
An AC EVSE I can hack in my sleep, the signalling is not complex. It is also done in a failsafe manner. There are many ways to stop a car pulling charge from an EVSE. Some, I definitely wouldn't recommend, which I'm not going to mention, because somebody.will...
If the CP wire is broken, the car will not charge. It has no possible hazards. Put a signal relay in the EVSE to break the CP wire. Run your external signal to the relay. Simple, cheap and safe.
I'm sure that you have talents that utterly elude me.
Re the lugs. I just had look in McMaster, no 88s. Could.you make one from a butt splice?