Lordy, How do we former military aviators ever get along in civvie street? No Guard feature....never monitor 121.5 or 243.0.....much less the HF freqs. And all that SAR traffic.....thousands of the things floggin around darting around the Robbies and Pipers....whats a guy to do I ask?
If it were as important as you think Crab....would not the civilian authorities have mandated a Guard feature on VHF radio equipment? Would not the AIP or equivalent mandate a listening watch on 121.5 and thus necessitate the Guard feature?
What is complicated here? You cruise up to the mountains to fetch a broken legged walker to the hospital....probably a flight that a HEMS bird could have handled unless there was some winching involved ....you see some other helicopters in your neighborhood....go to the trouble to demand they all un-ass your area.....and it is the civvie's that are un-professional and dangers to the military?
Do I want to make the legendary PAN call or even a Mayday on 121.5 and hope someone is listening....or on a frequency I am working or was working or one that I know someone is listening to? I would suggest the Guard freq's are a military thing in practice and not something civvies are going to use with any certainty.
I also note you put emphasis upon a TDA for over-land SAR flights....what about over-water SAR flights....you do TDA's for those too?
What protocol does your SAR Coordinator use to dispatch a HEMES aircraft vice a SAR bird?