Erasure Coding: Microsoft discourages using single parity because it can only safely tolerate one hardware failure at a time. If one server is being rebooted when suddenly another drive or server fails, there will be downtime. If there are only 3 S2D servers, Micosoft recommends using three-way mirroring.
The EC configuration depends on the storage setup (hybrid vs. all-flash) as well as the number of nodes in the S2D cluster.
EC in Hybrid configurations (SSD+HDD):
4-6 Nodes use RS 2+2
7-11 Nodes use RS 4+2
12-16 Nodes use LRC 8+2,1
EC in All-Flash configurations (All SSD):
4-6 Nodes use RS 2+2
7-9 Nodes use RS 4+2
9-15 Nodes use RS 6+2
16 Nodes uses LRC 12+2,1