Anyone knows if this works and if you can play a 4k movie (ideally with HDR) using this setup? I think this would be an intriguing combo...or I would just buy a 4k TV, which might be the smarter thing to do at this price point.
No the 5K display will not work with the iPad Pro. That display is based on the Thunderbolt protocol which the iOS devices do not support. The 4K LG will work as thats based on the standard DisplayPort over USB Type C standard.