With GR Based IV checked at PO item level, you can restrict MIR7 / MIRO prior to goods receipt. That means system does not propose any items in MIR7 or MIRO provided GR is not done.
If GR Based IV un checked at PO item level, you can perform Invoice verification prior to goods receipt.
Have you performed goods receipt after removing the GR Based IV in PO? If yes, Do not you still see the Quantity and Value in MIRO?