Generally speaking, if my partner and I are pretty sure they will be going to triage, we will let them know. If they understand and still want to go via ambulance, I make them sign, let them know about the incoming bill, and buckle them up. I would rather be sleeping.
Now maybe if I wasn't on...
Splint before moving them to spine board unless they are critical, then it is secondary.
If they are stable and a traction splint is applicable, do that.
Elevation won't help much with short term swelling. I wouldn't really move a suspected fracture, you don't want to make it worse, unless...