Jason Miller had a short, ’The Finer Points’ podcast interview with a member of SARSAT who monitor ELT’s. He states to never, ever activate a 406 unit at 5 min past the hour and only use the manufacturer’s test mode. It was informative but may not address all the nuances you’ve all been discussing.

Go to: https://www.learnthefinerpoints.com/podcast and scroll down the list to the Jan 20th episode, ‘Staying Found’.