请问8老师pending 130 and 485 to use AP leaving US

Dear Master 8: My parents filed 130 and 485 simultaneously in April with no approval yet. Yesterday we received the letter indicating 485 will be dealyed to approximately 6 months and potential interview waiver

-Can we file form 131 AP for my parents to leave US with both 130 and 485 pending? or do we have to wait until approval of 130?
-What approval form shall we expect before leaving US?
-How long can they stay in China before returning to US?
thank you very much!!!