Exporting images shot to tethered iPad to Desktop / external HD as session.

At last I have an iPad with USB-C, so now I can shoot tethered to an iPad running C1 rather than hauling a MacBook Pro to smaller shoots, such as branding portraits. 

However, I'm not sure of a "best" workflow to move the shoot from the iPad to my desktop. 

Did a quick test shoot, connected iPad to MacBook Pro and drug the CaptureOne.cocatalog over to my 24TB external HD connected to my MBP, but saw that it's a catalog file, not a session. I only use sessions in C1, never catalogs. So I selected all the files, File>Export>Originals>checked save adjustments and saved to a new session. Star ratings and a B+W adjustment I made showed up in the new session. 

The above seems a little convoluted but feels better than using iCloud or any cloud, definitely better than using Capture One proprietary .eip format (sorry, but Canon RAW formats will have a longer archival life than a Capture One format). 

Am I correct in assuming from the above that in shooting to Capture One for the iPad Capture One is only working as a catalog and it's not possible to create a session? 

Lastly but importantly, what's the best way to completely clear all RAW files, caches and data from the Capture One app on the iPad? With limited storage I want to keep this iPad as lean and mean as possible. 

Thanks for any input or suggestions!