@blankmash The problem is not related to raised crossings. Some apps (namely StreetComplete) ask users about kerb heights on crossings. When the crossing is mapped only as a node on a road, it adds kerb=* to that node. This is the approved way to tag kerbs on such crossings (https://wiki.openstreetmap.org/wiki/Tag:barrier:kerb#Alternative_on_crossings).

The problem is that iD's validator suggests to add barrier=kerb to these nodes which makes routers think that there is a kerb in the middle of the road (which is not the case). The bug is currently being tracked (https://wiki.openstreetmap.org/wiki/Tag:barrier:kerb#Alternative_on_crossings), hopefully it will get fixed soon. Until then, please ignore that warning.