Here is an example of my friend.
Come to USA with F1 visa, change his status to H1 after he find a job, but no H1B visa on his passport.
File 485 and get AP, travel out USA and come back with AP, I94 states his status is AOS.
Continue working for orginal employer without EAD.
Laid off one month ago, luckly find a new job soon. Have filed H1B transfer, still waiting for the approve. The lawyer who help me say it is OK for him to file H1B transfer.