Actually I should have simply entered 2000000000 since Hard Disks are sized in TeraBytes not TebiBytes.
The advertised Size of a HD is in Terabytes, orders of 1000 bytes, but the Data is stored in TebiByte or orders of 1024 bytes.
So you do need to use 219902325552 for 2TB of data.
Also I did a local Test.
with the registry value maxUserDefinedPreviewsBuffer removed from my resgistry
The Next time I started iStripper, my Demos started to be deleted.
So I believe you do need to have that key to prevent the demos from disappearing.
You get the demo's upon download,
but the next time or next day you start up iStripper, if you have exceeded the demo size limit
they are removed.
So I recommend for anyone who wants to Keep all of the demos
add the Registry value, or for a Mac add it to the preference file.
Link to the post when this was implemented.
https://www.istripper.com/forum/thread/36009//1?post=529871