I have seen some users file system calls stall due to the EFS quotas. This was on a workload much tougher than WordPress. I haven't run my own NFS for compari

I have seen some users file system calls stall due to the EFS quotas. This was on a workload much tougher than WordPress. I haven't run my own NFS for comparison. I recommend reading the NFS v4 spec. AWS has all the pieces to implement the protocol as well as anyone can.