What are the best ways to manage wallpapers on multiple monitors? - eviltoast

I recently figured out my new setup, but one thing I’ve been struggling with are my wallpapers. I use 3 monitors, one 21:9 and two 16:9s, one of which is portrait. As a result, my wallpaper situation is messy since wallpapers for one don’t work on the others. On my old setup, I just had a big folder of backgrounds I collected over the years set to be a sideshow using the default windows settings, and I’d like to do something similar, but with a specific folder for each monitor. I’ve tried the steam wallpaper engine, but to do that, I’d have to individually import each background as a new wallpaper which would be far too intensive given the volume.