Adding a DC Server Rack to my Enphase System

[Ampster]

I have been looking at the Mojave for a few months now. It is the only think i can see that explicitly supports AC-coupling (frequency shift/etc). Outback refers to it now as UL 1741-SA.

UL1741 SA and SB are the protocols which allow AC coupling. All inverters are required to follow UL 1741. I had an Outback Skybox and it had a very good AC coupling algorithm.

AS far as i understand the battery charge/discharge settings have preset and custom. As i understand you can plug in any battery; including LiFPO4.

Yes you can use any battery with an Outback inverter by using custom settings. If you want communications between your Outback inverter and the BMS you have to use an Enersys battery such as the Outback Mojave battery which is designed to integrate with the Mojave inverter. Enersys is the parent company to Outback.