Thanks @SvenF. An inaccuracy can mean the difference between a proposal being passable or not. This could also mean some undesirable indeterminism. The subnet could appear to meet the IC Target Topology one second, and not the next. I imagine physical audits wouldn’t be able to be used as a reactive measure (but something scheduled and few and far between).
I suppose the most important thing is the history of the nodes apparent location. If this is tracked minute by minute, or hour by hour, then transient blips due to the network conditions could be more easily established (and ignored).
Maybe part of the node rewards monitoring should be responsible for logging the apparent location of each node over time. If it deviates too frequently and/or for too long, then it becomes a problem (whereas transient discrepancies could be ignored)?