The adoption of Open Submarine Cables allows purchasers to select the wet plant and SLTE modem vendors separately but introduces complexity in the validation of system performance, as the wet plant can no longer be defined by modem performance when modems are selected as part of the wet plant. Coherent optical modem functionality continues to rapidly evolve and introduce new performance measurements via parameters such as ESNR and SNREXT, which fill out the suite of parameters. The following handbook outlines additional use cases and considerations for simplified Open Submarine Cables link engineering.