What are the post sale options for inventory that did not sell through Simulcast?

They are posted to OVE, Smart Auction & Openlane:

SmartAuction®: This wholesale website sells off-lease, rental, fleet, and dealer-consigned vehicles. Better yet, smartphone compatibility makes bidding easy — even on the go.

OVE.com: OVE.com features the largest selection of online wholesale vehicles in the industry. View the vehicles we’ve listed today.  

OPENLANE.com