Interesting question. I would be sure that I had two good sources light (three might be even better) - useful in first aid as well as more normal applications. At least one would be a headlamp.

Platypus makes several containers that might fit very well in some of your vest pockets. Very sturdy and they will "shrink as you drink."

Consider stashing a smallish prybar somewhere in your vest. I am thinking of the gadgets that are available in your local Home Center, anywhere from 5" to 15" in length - very good for heavy duty prying and scraping. I would also pack a pair of leather gloves - deerskin are the best, light, compact, and quite tough.

A good multitool, anything you like as long as it's a Wave, would be useful.

Additional FA items, oriented toward trauma, seem like a good idea.

Best of luck to you.