Hi,

as far as I know the cache folder is used for caching applications which you deploy via WSO.
Do you have a File Storage configured (All Settings > Installation > File Path?)
There is an option to disable File Storage Caching. If this is activated the Device Service Server will cache the Packages while they are requested by the clients.
If you have a big amount of internal Apps, this can cause the big amount of Data.
This is mentioned here under "Allocate Sufficient Hard Disk Capacity": https://docs.vmware.com/en/VMware-Workspace-ONE-UEM/services/ReportsAnalytics/GUID-AWT-FS-INTRODUCTI...
I think if you disable the option, the content of the cache folder will still be the same because WSO is not deleting the files if you disable it afterwards But it will not grow further.

I can't confirm that deleting the files in the cache folder will not cause any problems, because I haven't tried it.
But from my understanding the DS will catch the files needed from the the Fileserver everytime an installation is triggered by a client. Therefore it shouldn't harm to delete it.
Also if you need to replace a Device Service Server you will reinstall WSO on it and there will be no cached data in it. That's another reason why there shouldn't be a problem.

If you find out another reason why the cache folder expands this way, please let me know.

I hope this helps a bit.

BR Mario