The 4th Powerlift: Lying Triceps Extenion
 

Going to add this. Thanks to Josh for the suggestion. Buying an EZ bar today.

LTL suggested I tried a dumbbell variation, but with my spinlocks it wouldn't work very well.

These getter dun for me. Hope they work out well for you.
I would suggest you warm up with a lighter weight to "loosen up" the elbows a bit.
For me they can cause a bit of elbow discomfort while performing them if I don't do a warm up set.

For anyone that uses mobile free-standing squat stands, they can be placed back-to-front further down the bench, at the point where the arms would be in extension and that permits the load to be taken from the stands without a spotter.

Placing a low "catch" item (aka safety bars, stacked books etc) each side, below the head (lowest point the EZ bar will reach to) in case the last rep is just too much to return to the starting point.

This is actually how I was taught by a bodybuilder to do skull crushers to make them more effective. Good times.

LtL

That ROM would destroy my shoulder. I can do the crusher ROM with respectable weight and destroy the Tris. I personally dont need the added shoulder extension.

Im not saying this to be sarcastic in any way. Anyone with shoulder issues will understand.

I'm curious whether you've actually tried them or you are just assuming they would bug your shoulder(s).
I've had a couple shoulder issues, probably minor compared to yours, but I have always been able to perform this movement without any problems what so ever.
Even during times when my shoulder was tweeked enough that I couldn't do many lifts (ohp, incline bench, db flys, etc.), I was still able to perform this movement pain and discomfort free.

Not trying to be confrontational, just trying to help.

Yep, tried em. Now grant it I can do them at a very reduced weight. Ive had two injuries, one being a total A/C separation with surgical repair and a Rotator tear. My functional ROM has been greatly reduce in my left shoulder (overhead ROM).

Good stuff, I like the Bent Arm Pullover with a barbell and always found that to really work my triceps a lot. It's a very similar movement.

Does anyone ever use a band to keep their elbows from flaring out? Just curious, on this and seems the right place to add it considering the exercise.

I have one shoulder that isn't as flexible as the other, in that it won't permit the arm to come in to the centre-line of the body as easily as the other arm, not even with the hands clasped behind the head and trying to touch elbows in front of the forehead. Probably caused by the TOS but that means one arm is liable to flare because it finds the movement pattern easier but since that may not be great for the shoulders a band around the arms help to prevent excessive outward flare of that arm.