I think the reality is that searchers won't expect the lost party to know ground-to-air signals. Anything that makes your position visible from the air will get checked out, whether it means "require doctor" or "serious injuries, require medevac" or "require assistance," or even "all is well, send pizza" for that matter.

(That last one is a circle, divided into eight segments. Remember that, it could save your life one day.)

This is one of those cases where information from military survival manuals isn't really relevant to the civvie side. Those signals are really for military communication sans radio, rather than universal distress signals. You don't need correct signals if you've been reported lost; if not, you need something that anyone will recognize as a distress signal.

Michael Green, a British humour writer, discusses distress signals in his book The Art of Coarse Cruising, complete with photo illustrations of "correct" and "incorrect" signals.

The "incorrect" photo shows a boat flying its flag upside down, ball hoisted over signal flag, etc., while the crew calmly await rescue. The "correct" photo shows a boat displaying no signals whatsoever, but with the crew in various comic poses of panic.

It's funny, but it's true.