I don’t have the time to Google atm but there’s a growing body of experts shifting to the “it doesn’t actually matter”. Here’s a podcast about it but there are definitely more sources to find: https://www.abc.net.au/listen/programs/lifematters/the-myth-of-good-posture/13864470
I saw another comment in the thread about ensuring you get movement in – that’s what my PT hammered into me.
Kinda scared to update in general. I’ve heard it starts checking for tether provisioning and you can maybe uninstall updates for carrier services to fix it, but maybe not. Still running 13 actually.