Can the 787 mini navigation display be controlled independently from the ND?
The MiniMap is not an option, it's there as standard.

It's fixed at 20-miles range; the optional items are Wxr, Terrain and Traffic. The classic STA, WPT and ARPT from the ND are not available.

The MiniMap shows ADF needles, whereas the ND shows VOR needles.

The MiniMap looks like a development of the previous compass-rose at the bottom of the PFD, but it's mostly of little practical benefit. The major use of the MiniMap is to show Terrain while having Wxr on the ND, a dual-view that wasn't possible before.