Actually, I think this debogonizing scenario is the kind of situation where "compound" measurements can make sense as probes number 929, 843 and 325 depicted in these graphs and belonging to ASN 48954, 15764 and 20825 respectively, dont seem to be able to ping 128.0.0.1, but, 128.0.24.1 pingable address, on the other hand, is fully available from all the probes from ASN 31027, 6750, 5539, 8365, 42760, 25538, 35706, 345954, 2108 and 719.
If same probes could conduct pings to both prefixes we could get an even more accurate picture of the portion of the network Atlas covers and monitors.
Back to the routing-wg topic, as Alex Le Heux is CCd, I think at least AS 48954, 15764 and 20825 contacts can be already be notified on their seemingly outdated filtering, as those red bands are "horizontal" enough to do so.