Whose “zone 2”?
Sorry, but you seem to be laboring under the common misconception that “zones” are discreet, and everyone agrees on them.
The reality is that they are defined.by rather arbitrary, disputable cut points, because all physiological responses (and resultant adaptations) reside on a continuum, such that any such divisions are largely a mental convenience.
TL,DR: Fatmax, LT1, LT2, etc., are really all just different measures of the same thing.