Unless OP is flying on dates where SFO-PHX is available seasonally (basically “baseball spring training”), OP is looking at something like LAX-PDX/SEA-SFO. That’s probably 6-8 hours of additional flying and connection times for a flight that’s 1 hour out of LAX. Flying might be fun for you but I’d probably buy the positioning flight like OP suggests instead enjoying gormay polenta and kale for most of a day after a longhaul flight. If OP buys an AA flight they even get acces to AA/OW F lounges per OW lounge policy (not true for AS flights).