In the Wikipedia article Method of Levels, on 30 September 2018 an editor called ‘Biogeographist’
deleted the “Testing” section and on the Talk page recommended a more complete and better documented section describing how MoL has been validated.
The original “Testing” section can be recovered from this revision as it was just prior to the deletion. The only reference that it cites is Mansell, Carey, & Tai (2012), and that reference is imprecise, no page references to places concerned specifically with testing and validation.
It would be good for someone to fix this who has been actively engaged with validation of the method.