X1 still uses and can use DX plugins. They just have to be the same bit-ness. So 32 bit sonar can use 32 bit DX plugins, 64 bit sonar can use 64 bit plugins.
You can install 32 bit sonar on a 64 bit windows system and it will run fine. As well as install and use 32 bit DX plugins on a 64 bit windows system.
The problem comes when you want to use 32 bit DX plugins in 64 bit windows. For that you need a wrapper like DXshell or Acon Effect Chainer that will run DX plugins as VSTs, then you can bit bridge them. But that's a bit of a hassle.
If you really need 32 bit DX plugins, just run the 32 bit Sonar. No fuss no muss.