H1B to L1A on 7th year while I140 is pending in EB1C

[ramuka]

Dear Experts, 

I have started my 6th year H1B. My company will be filing I140 in EB1C. Note now for EB1 the priority date is no more current. 

My company advices i can change from H1B to L1A and wait for I140 approval within extra year or EB1 priority date becomes current. So can apply for EAD and AP. 

1. Is it legal other than matching minimum requirements ?

2. Should i maintain the same non immigration status as when I40 is applied until its is approved?

 

Thank you