Secure comms as much as possible was also a recommendation. But it requires the other end to have the same. That's not always an option. TETRA is not available to most people and so sometimes you have to resort to standard comms, TETRA also doesn't have perfect coverage. Analogue vs digital is a debate not to be had here as the thread may have drifted far enough already.
Tight protocol is another, but again not everyone is part of the SAR organisation.
Accessibility is only a matter of LOS at any particular moment.
I pay for police, fire, ambulance, refuse collection ... I have no desire to track them. As I say, those that need to can, the rest is voyeurism. To think they "may be hiding something" now that is extreme paranoia.
The scenarios are not hypothetical, so your opinion of the likelihood is of no relevance. Whether UK SAR considered them I have no idea. I was simply offering my view that other SAR operators have answering a specific question earlier in the thread.