回複：9月遞NIW 140/485, 140 已批. 現老板要沒錢了,請教各位重要問

Transfer and new H-1b = same. So you don't have to worry. If you can find a basically same nature of job, e.g., research to research, that should be fine. However, I don't think you can go back to F-1, because your I-140 is EB. Why just try to find another job? It should be ok.
BTW, do you think it is a good idea to go Canada if you can stay here?