Kind of off-topic'esq but what about going all M.2, as-in:
Asustor Flashstor 12 Pro FS6712X with 12 M.2 SSD Slots. Plus 10GBe port.. 6x2TB WD Blue SN570's -
This can run with 24GB DDR RAM max, tested 64GB, 32GB RAM no joy, but 16+8 (or x2 x8GB) runs fine.. A 2nd 10GbE port would be perfect tbh...