Theoritically, you can put Four Reference cards Navi in MSI X570 Godlike. My current tower cooler blocks the first GPU slot. Waiting on 3950X before actually putting the bonus MasterLiquid AIO from MSI X570's promotions.
Anyway, I tried with three GPUS (one custom AIO cooled, two reference coolers) and it works just fine. Their temps are not catastrophic either; With fan speeds less than 50% (therefore noise is tame), the GPU temps are around 65-75 oC, with memory junction temp around 90 oC.
https://youtu.be/IDsYGdhxayAAfter 3950X is here, I will get one of that and another reference card 5700 and my goal of having four GPUs in one motherboard will be achieved.
For now the RX 5700 yiels around 48-49 Mh/S each with maximum GPU temps around 70 oC with memory temps around 90 oC, with fans running below 40 %.
This RX 5700 reference design is just great for me.