Hello,
Unfortunately, currently there is no way to set the temp folder or check whether the network files are cached or not.
If you want to play the network songs "explicitly" in offline mode, you can download the files to your phone.
- On "Explorer", go to the network folder that contains songs that you want to download.
- Click the Edit button on the lower-right corner.
- Select files/folders that you want to download.
- Click "Cut / Copy", then an icon will be appeared on the upper-right side.
- Go to the local folder.
- Click that icon and click "Copy Here".
- The selected files/folders will be downloaded to that local folder.
There is a plan to support "offline mode" for the files, where you can manually toggle some network files to make them playable in offline.
Thanks.