Vendor Item Import doesn't set Purchase Unit to Largest UOM

Vendor Item Import doesn't set Purchase Unit to Largest UOM
CFA Testing
Store 00440 has 2 active vendor items assigned to Soda, Barq's Root Beer item (itemid = 2099, itemcode = 1621)
002095 SODA, BARQ'S RT BEER BIB - Purchase UOM: 5 Gal. Case
079722 SODA, BARQS RT BR 2.5 BIB - Purchase UOM: 2.5 Gallons

select DiscontinueDate, * from tbvendorentityitem with (nolock)
where itemid = 2099 and entityid = 269

Inventory entity item Purchase UOM is 2.5 Gallons instead of 5 Gal. Case

select StocktakeUnit1ID,* from tbentityitem where EntityID = 269 and itemid = 2099 – 176
select * from tbUnitOfMeasure where UnitOfMeasureID in (176, 184)

My understanding is that even if Vendor item import sets inventory entity item StocktakeUnit1ID UOM using the last vendor item in the file, there is still a process that runs after the import that should update it to the Largest UOM if there are more than 1 active vendor items assigned.