Simulataneous online and offline bidding scenario in two part bid scenario

We have below scenario in SAP SRM 7.02 with extended RFX:

1. Two envelope RFX is created with multiple suppliers
2. Few of the suppliers want to give their response online while others want to send their response through hard copies (through post/courier)
3. The buyer wants to open the hard copy bids along with the online bids exactly on the bid submission deadline
4. After opening the hard copy bids, the supplier wants to create the RFX response in the system on behalf of the supplier after the bid submission deadline for the hard copy bids
5. But system doesn't allow to create bid response after the bid submission deadline

Please inform what is the best possible way to handle this scenario.