Ever since the creators update, the command I normally use no longer works:
control /name Microsoft.Personalization /page pageWallpaper
Technically one can go in the modern settings, choose pictures and then right click on them while they're on the small 5-picture wide strip and choose which monitor. (Woe to those with more than 5 monitors then.)
But this means I have to go to through the process twice, because every time you browse for a picture it gets put on both monitors. This is unnecessarily involved and tedious.
Is there some way, free program or hidden windows control that makes this process easier?