Well I think we need to distinguish between practical latency measurements on earth, where it's mostly a matter of rejecting dodgy data / outliers etc.., and de

Well I think we need to distinguish between practical latency measurements on earth, where it's mostly a matter of rejecting dodgy data / outliers etc.., and detecting systematic latency bias that is theoretically impossible to detect. If you could get around this problem just by using a network of N nodes, then you could do stuff like measuring an absolute reference frame, thereby violating special relativity.