But self replicating nanobots is entirly plausible
No one really knows what STIMpacks are, they could easy be nano bots that heal wounds then die and get filtered out
Also it's not that implausible to quickly heal bone, god knows we've got plenty of crazier stuff that we've already pulled off
I could certainly see quick sealing of flesh wounds with some sort of nano-injection thing to hold your blood in and promote wound healing (maybe mix some stem cells or something similar in there to speed things up), but I don't really see it actually being able to fix you with flesh. As calculations have shown, if you try and pull the amount of energy you need to fix even medium cuts out of your body at once you end up starving yourself, and to reconstruct it with technology would require the nanobots to recognize exactly how your body was constructed before on the cellular level, something that is going to be different for every person.
Really I don't think we're going to be going too much farther on first aid battlefield medicine for quite some time. My guess is that most of our upcoming developments are going to be in making it easier to carry hospital equipment to and from battlefield hospitals, and less on quick fix first aid stuff.
I plan on getting anything that lets me expand my senses once it's deemed plausible and safe.
There's already a few (mechanical) things that expand senses other than the basic 5 out there. For example there are tiny magnets you can put into your fingertips to let you sense nearby magnetic fields, or things like the
North Paw that you can use to augment your sense of direction.