ItemSiteListItemSite should be called ItemSiteListItem. Item should relate to ItemRelation. Item is way too bloated for a list item. It needs to be nested as well since items are not loaded into the cache (potentially too many). Shouldn't need to grab inventory UOM, that should be available on itemRelation. Is Sold should be added by Sales extension and QOH by inventory, the latter we haven't started yet.

Strip down Itemsite relation to the following
isActive
itemRelation (isNested)
siteRelation (isNested)

Where are Site orms?