Hello,
You can install both Windowblinds and Curtains in your system. If you open up Curtains. Initially, Curtain will unload Windowblinds and set it to Official Windows 10 theme. Once you load/click any curtains theme it will auto load for you. Which is very fast.
And if you wish to change back to Windowblinds. You can just open up Windowblinds and load any Windowblinds theme. Sometimes WB don't load properly, you just need to restart explorer.exe or reboot.
Thanks
Basj,
Stardock Community Assistant.