The earths magnetic field is not constant. I don't know how much it changes, but I know magnetic north drifts a bit every year. And every once in a while the field reverses (IIRC we are like 10k years overdue for a reversal if we read the history of them right - a lot of guesses go into that of cousre)
There’s nothing saying that you can’t do a re-localization or remapping path with basically infinite frequency, or any frequency that we know that there is variance around. At a minimum then, it becomes a better standard for which other things can bear on.
I didn't mean to imply that it wasn't useful for practical purposes. That is what the article is about. I just meant to point out that there are limits and disadvantages to work around. I'm expecting to make this useful they will have to have a team to constantly remap the earth, and send those updates to whoever needs the information.
