Last weekend while goofing around with other stuff on my bike (82 GL), I added a few redundant grounds just in case. IMHO, the sooner you add a redundant ground (or two), the longer your other cables will last.
I didn't have any grounding issues, so I chose to use small 12 ga black wire (with crimped ring terminals) that I had laying around. I ran a long wire from the ground lug on the starter case (shown below - different on CX I think) up to the forward mount of the ignition coil stand-off (shown by pinkie in next photo).
(

)
From there, I added two more (black) 6" 12 ga pigtails, each going to the rear mounting bolts areas on each coil (shown by index finger).
(

)
Certain overkill for sure, but it cost pennies and only took a few minutes.
Oh, speaking of overkill, I decided that having the two coil connectors sticking up out of the harness, just below the tank (hitting tank?) was a bit annoying. So I covered them with a (new) scrap of fat convoluted tubing to shield them form Murphy's gremlins - see second pic right under Dr Doofus' fingers.
I think I might add another to the regulator mount also.