I gave that a go, hope you don't mind if I share my experiences.
First of all, there are so many options, that I felt completely lost.
I'm also a little sensitive regarding tools, that will change my wallpaper setting (having three monitors on Windows 10).
So, what me annoys first was, that, when starting it up, it immediately removes my initial setting showing some colored desktops.
I thought I will have the chance to test something before it starts working.
The next step was to close it, which didn't work, I found the tray icon and used a right mouse click on it (because all other tray icons I have are reacting on a right click) and nothing happened.
But well, I'm not a complete moron, so I tried a left click, et voila, the context menu showed up (feels un-intuitive).
I was looking for an exit menu entry, which wasn't there... opened up the GUI again, and missed the icon on the right bottom corner, so I had to use task manager to kill it.
Then I opened it up again, because I thought, that can't be correct, there must be an option to exit it correctly, and finally saw that icon.
Anyway, even after ending it up correctly, it didn't restore my initial desktop settings.
Long story short:
It might be a cool tool, if you know exactly what you are doing.
But it should really store the wallpaper settings at first run, and restore it, when quitting, or maybe through some menu entry called "restore initial settings".
And the left click to open up the context menu also feels odd.
Your config files also look strange, why not use the preference lib, or JSON or XML?
Most people feel comfortable with those formats.
Anyway, I might give it another look, when I have more time, but it is definately nothing for a quick trial.
Now I have to restore all my wallpaper settings, see you later