for SO2V you just need one serial port on RX1 while in SO2R mode you need a additional com port on RX2. This is enough for N1MM to properly command both vfos or both rigs.
For the S&P operations you need a dedicated bandmap (on second VFO or on second rig). Then you can use the following shortcuts to move from one spot to another
Ctrl+Down Arrow – Get next spot higher in frequency.
Ctrl+Up Arrow – Get next spot lower in frequency.
Ctrl+Alt+Down Arrow – Get next spot higher in frequency that is a multiplier.
Ctrl+Alt+Up Arrow – Get next spot lower in frequency that is a multiplier.
Anyway there is a missing point with EESDR audio control. At the moment it doesn't support the OTRSP protocol, so you can't use this nice and powerful N1MM feature. So you have to make a choice between listening both vfos on both ears or listen one vfo for each ear. You can find other informations in the Addendum Manual by Erik.
On the other side, 5MContest can go over this tricky setup because it can control EESDR using the TCI protocol. Once you configure the TCI connection it can handle one or two vfos/rigs with their Key & Ptt lines. All this can be done without hw or virtual serial ports and without hw interfaces. You may find other informations on the following link https://translate.google.it/translate?hl=it&sl=it&tl=en&u=https%3A%2F%2Fiw7dmh.jimdofree.com%2Fsunsdr2-pro-pages%2F5mcontest-guida-parte-1%2F
In addition my whish is, one day, EESDR will provide a OTRSP dedicated com port and the TCI protocol will be enhanced with audio control commands for both receivers.
I hope it can help you