LTP and strain query

@ManofSteele @stephencheung I would appreciate your view on the following:

If during very long multi-day back to back ultra cycling races (with limited refuelling stops, no sleep or max 3-4 hours sleep) TP effectively ultimately reduces down to LTP, why and when would it be justified for a coach to ignore all/most strain in the zone which typically would be qualified as (Coggan) zone 1 based on power meter readings ?

I am confused as to why one would manually cut out / adjust strain accumulated in this typical zone 1 area, especially if wattage in this range can feel a lot harder when carrying so much fatigue and arguably does still have a metabolic cost ? Low strain is still strain. I can’t find any scientific reference for such practices.

I would appreciate some pointers if there is any literature on this or alternatively some feedback if this is indeed common and to be recommended.