I have a proposal for a "new" operational mode for NB.
The traditional QSO using USB in all frequencies is half duplex. This is due to the fact that is impossible to Rx during Tx. Using USB is possible two stations or more to talk at the same time without interfering each other.
The proposal is that two or more stations talk together like a telephone conversation. Of course callsigns must told every few minutes according to ham radio laws.
This will provide a more "natural" mode of communication that is impossible to implement with out QO100.