I'm using 2014 mid MacBook Pro 13 retina. I was not happy with old safari and with assist of the "open legacy boot loader" I've upgraded it to Sonoma 14.6, and it was working great for couple of days. I was satisfied but somehow I decided to upgrade to 14.6.1 from macOS system. and of course that was a Terrible choice
the system was crashing after login with a broken graphic screen. I tried some solutions but didn't succeed. the boot loader (includes Sonoma 14.6) that compiled with open legacy boot loader does not work anymore cause of apple's policy which does not allow install older system.
after that, I open safe mode, backed up my files to usb, made a factory reset and deleted the harddisk.
then reboot with cmd + r keys. macOS downloaded from net, fresh install started and welcome screen appeared.
and version "maverick" appeared to start installing procedure. but, can't continue that cause maverick does not supported os on my MacBook.
After that, I downloaded Big Sur installer on my other Mac mini. then prepared a 64gb usb stick installer. Booted MacBook with "opt" key. Plugged the stick to MacBook. Viola! Big Sur installer appeared!
Sorry, I can't explained every step detailed. But I hope this experience may help to someone.