I am co-author of LOD Coloration, Level-Of-Detail visualisation tool for Unity Editor. Buy now:
https://assetstore.unity.com/packages...
Preview prefabs and models LODs distance in realtime in scene window.
LOD Coloration is an additional shading mode for Unity, which shows real time the actual LOD of models in 3D view.
With LOD coloration you can easily spot those models which lack LODs or their distance is too high.
Website:
pzazcode.wixsite.com/website