'Post-crash protocol', for me at least, includes 3 main stages:
1. The things we can do in advance of any flights to make sure we can quickly find our craft if it goes down somewhere unobvious.
2. The things you do immediately after the accident when you find the craft.
3. The things you check about the craft once you have restored it to what you hope will be working order.
Stage 1 is covered for me with the addition of a small tracker. I use the loc8tor button tracker on mine, mounted on velcro just above the gimbal retention switch. I have never crashed my H, but before that I had a DJI-driven TBS Discovery Pro, and when that went down (NPE flight controller freakout), utterly invisibly in a cornfield, the tracker was able to lead me straight to it. It was such a vast field that I could have searched for days unguided and still not found it.
Typically, the things you should do at Stage 2 are related to making safe and crash investigation.
So that primarily involves disconnecting batteries / putting out any fire / making safe, then videoing the crash site and remains, complete with audio commentary in as much detail as you remember, something that is important we do asap after a crash so we don't forget anything that happened... if you have that and the telemetry from the flight the chances of finding out what went wrong are very good.
Whereas Stage 3 involves much more thorough than normal checks over the whole craft, and the hardware functions before first flight. I'm sure I don't need to tell anyone what those checks involve, and a lot of them can be done at home without any props on, but after that I do like to find a particularly empty field in the middle of nowhere to make the first flight tests after a crash, thereby minimizing consequences should anything still be wrong.