Hey mate 
Latest working config here: FluidNC Primo Config for FYSETC-E4 board - #2 by gritters
The downside for the fysetc-e4 board was only 4 drivers so I couldn’t do dual endstops. I never really understood the appeal of dual endstops until I started realising I was getting drift from my frame that I couldn’t easily fix automatically. Apart from that it was a perfect kickstart board and I was able to test all the hardware end to end very easily, including normal endstops and an xyz probe. Plus I got it as a freebie from a mate so the price couldn’t be beat!