To run multi-monitor you'd need the monitor to embed a DP-MST hub or embed a USB 3 video device if you only used a single port.
The alt-mode capability cannot traverse a hub.
More likely you'd have dual cables running to dual monitors. Each monitor could provide internal USB 3.1 hubs and associated devices plus feed 100W back up the line if needed.
I would think that the first monitor would have a thunderbolt passthrough for a second monitor connection... IIRC, the apple thunderbolt displays have things like ethernet, etc on the monitor itself, though I don't think gen-1 supported multiple displays on a single connection, it wouldn't surprise me if this one changed said passthrough.
