Latency of MCX512A-ADAT PCIe3.0/4.0 x8 and SFP+ vs SFP28 difference?

Hi guys, can anyone confirm getting sub-600 ns latencies?

Is PCI-E 4.0 providing better latencies?

Is there latency difference of using SFP28 10G and SFP+ 10G transceivers used in this NIC?

From what I know , there is no difference between pcie3.0 or 4.0 ; SFP28+ and SFP+