rj4

Went ahead with the suppliers suggested method, by not using the ATS port, as the delay is around 90 seconds and they stated that it is not that reliable.
The inverter is performing good so far. Over 120 days now running, and not one single issue.

The same question was asked on facebook yesterday. I only have a link for the group but look for the post: https://www.facebook.com/groups/1224829628388092
Basically the consensus I took away is:
Great product - Failure rate seems high but only because of the volume they have sold and because of the slow support/repairs when there is a failure which results in more people being vocal which is fair

Also note the position of your thermostat tube, it MUST be at 10am or 2pm (relative to the element) to function correctly. 

Geyserwise specify that you use the satchwell vfk11 in this use case (get the proper satchwell brand). 
We have quite a few like this. 
Geyserwise email and phone technical support is top notch if you need assistance. 
 

Updating here as I have finally managed to get the 2 wire USB-RS485 adapter working with my shoto. Thanks to @jetleewho gave me the names of drivers that worked for his Narada battery on another topic, I found an extra driver from Device Monitoring Studio that must have been conflicting.
The drivers needed for this FTDI adapter should be automatically installed/found by windows: ftser2k.sys, serenum.sys, ftcserco.dll, ftserui2.dll
Once I found out that the shoto uses a Seplos 100A BMS I managed to find a ton of info on diysolarforum and on boards.ie, so shout out to those guys over there, they've done a lot of research on the seplos.
The pinout is as follows: Pin 1 on the RJ45 plug goes to B (D-) on the adapter and pin 2 goes to A (D+)

You can also use pins 8 & 7 (respectively) instead as the pinout is mirrored on RS485 port. I've actually used 1&8 for D- and 2&7 for D+ for a better connection with these flimsy wires as they are joined anyway as per the image below.

The software needed to connect is called "Battery Monitor V2.1.8" by Seplos and you can find all the necessary info and files here: https://drive.google.com/drive/folders/10pxgNLHovcDZRVGrCZsSkfecBrRw-AdW
Please read the manual before playing around as there are some things that need to be set up before connecting to the battery and make sure you set the baud rate to 19200.
All the info you need, including 6 temp sensors, SOC, Cycles, real time logging and lots more:

 
Enjoy!