Can you disable power from LG Ultrafine monitor to Mac?
Please disregard. the issue that led to this odd question has been resolved with an recent LG firmware update.

I have two UltraFine 4K monitors connected to a 2016 MBPro. When the Mac went to sleep both displays went to sleep, but only one would wake.

This has been resolved by the latest firmware.

1.) InstaLL LG Screen Manager. LG site still showing old version.
2.) It will push the most recent version. v2.06.
3.) Upgrade your monitor to the latest firmware. (3.11, 3.4, 5226, 3.04, 0.2f)