ATB

As much as I would say it makes sense to get the Sunsynk or Deye, unfortunately it's not a purely off grid inverter. There is a large portion of that machine that is Grid tied & you paying for quite a bit of that portion of the machine which you will not make use of. I would suggest the either 3 X 5kW Voltronics machines on Single phase to make up the 3 phases. Or the infiniSolar 15kW 3 phase machine. 
It supports Pylontech batteries & if you wanted to buy the best priced Felicity Solar batteries the RS485 would pair with all the Voltronics inverters I mentioned above. 
The 5.6kW OGS5.6 is out of stock but the 7.2kW & even the 10kW single phase machines as purely off grid cannot be beaten in terms of price & reliability. 
The infiniSolar machine is the latest version of that machine & I know many will shoot it down based on the older version. I have worked with this machine & it is light years ahead of the old Infini. 2 AC output load ports that can be Remotely controlled & configured to cut off at a specific % SoC. 
But without the Grid I would not waste valuable budget on the Deye/ Sunsynk. You on a farm. You need redundancy & also a machine that gives you the most options as possible. All the Voltronics machines offer that. 
I install both types. This user requirement meets the Voltronics hands down.