I took advantage of the holiday downtime to replace the original trigger coils with the pair from the XJ harness.
Below is the plate with OEM coils, grey wire coil dismounted, orange still screwed down. I cut off both coils right at the body to preserve harness length. I re-used the sheathing material on the XJ coils, and pulled the wires out thru the original grommet. Be sure to put the new orange wire coil where the original orange wire coil is mounted; don't want to mix them up.
XJ coils mounted. Note the ground wires are bonded, the OEM harness is the same. You'll have to cut off the ground wire bond so all 4 wires can pass thru the grommet. Don't cut orange/grey wires yet- that comes later when you splice into the harness.
XJ coils mounted, harness laid up and trigger plate mounted; showing wires fed thru the original grommet. Once you cut the original coils off, the wires can be pulled out thru the grommet, and wires for the new coils are pulled through.
This is the splicing situation. Note the bonding clamps on the OEM harness, cut them all off. Then lay up the harness and get the cut the trigger coil orange and grey wires so you can make a good splice into the matching color on the OEM harness. The black wires may be short- they were for me as seen. I used spare lengths of OEM black wire to make up the splices. I like to solder the splices, apply a good bit of dielectric grease and then heatshrink tubing.
Good news is the engine starts and runs fine! It will need a bunch more testing, and I need to torque all the fasteners, wrap the harness with vinyl electrical tape and tie it down better- but so far so good. And another picture of what the spliced harness looks like too.