Pending PERM and i140 are usually not affected by H1B transfer application as PERM is for future job position.
Your situation looks a bit tight with respect to timelines. You will have to definitely file i140 in premium if you want to make file H1B 7th year extension using i140.
With 17 months in hand to max out date, do you think timeline will be tight to get i140 approved ? Max out is in July 2020 and not July 2019. Thank you.