Shimano Metrea ST-U5060-R compatibility So I'm trying to find out if Shimano Metrea ST-U5060-R would be compatible with any Shimano 11 rear derailleur?

Also, would it also be compatible with the T4700 Tiagra derailleur since it seems to be using a 11 gear pull ratio (even though it's a 10 speed derailleur).

Or do you really need to stick with the Shimano Metrea derailleur in order to use that shifter?

Same question with the front derailleur.
The Shimano compatibility charts say that Mattrea ST-U5060 is compatible with RD- R9000 (Dura Ace), R8000 (Ultegra) and R7000 (105) front and rear derailleurs.

Here are the compatibility charts - 

Rear drivetrain: http://productinfo.shimano.com/#/com/3.7?cid=C-453&amp;acid=C-454

Front drivetrain: http://productinfo.shimano.com/#/com/3.7?cid=C-453&amp;acid=C-455

Unsurprisingly according to Shimano Tiagra 4700 appears to only be compatible with itself. However, if someone has tried Tiagra derailleurs with 105 or Ultegra shifters (or vice versa) and knows it works, then Matrea shifters will work too.