Let me explain you that there is no way to avoid files caching in CloudMounter.
The cache of files are created on your machine first. Then, after the upload of files is finished and the drive is unmounted, or CloudMounter is re-launched, cache will be automatically cleared.
Also, every time you open the file the cache is downloaded locally. The preview of file works as opening the file.
So, when in Finder Columns or Icons mode is, the file starts uploading the preview of this file. So the cache is created.
In such cases, we recommend to enable "in list" mode in Finder. It will prevent the download of unnecessary files.