A marketplace facilitator is held to the same $100,000 look-back test and, once over it, remits Retailers' Occupation Tax on sales it facilitates. A facilitator that also makes its own sales registers two sales and use tax accounts and files separate Form ST-1 returns, one for its own sales and one for all marketplace sales.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.