After you file

@DoninGA Thanks for your reply. I still have 2 questions:

1. In my above case, changing the address will not impact my already filed and refunded tax port. Is that correct? I just need to notify IRS. 

2. If I change address before filling the tax report, according to the previous post "How do I change my address", I can directly enter my new address, and IRS will update the address record when processing my tax filling. Is that correct?

Considering the processing time (6-8 weeks), I just want to compare which way (move first then tax filling or tax filling first, wait for refund then move) is better? Thank you very much.