Well, you can always count on Dopers having opinions that they’re happy to share! But srsly I don’t think anybody, including Miss Manners, is really going to object to your (or anybody’s) choosing to orient the bed linens in whichever way is satisfactory to all the occupants of the bed.
The main reason that etiquette authorities exist is to provide decisive guidance on zillions of fundamentally arbitrary but impactful choices that random individuals would otherwise waste massive amounts of time and energy disagreeing about. Forks on the left or right? White shoes in winter? Hats worn indoors? Shake hands or bow? Which is correct? Does it matter?
No, not really. But because most people learn these sorts of trivial conventions as part of routine everyday behavior, it can be disproportionately socially disruptive for them to be done “wrong”.
So Miss Manners and her ilk undertake to be the referees who will make decisions about rules compliance, so that everybody else can get on with the game.