@David45, I run TOS on 2 computers simultaneously. Whatever, I create, save, edit in the way of my ' Charts, Layout, Custom Studies, and Study Sets' on one computer; appears like magic on the other computer. Somethings update immediately however to see the addition or changes of custom studies; I have to sign off and sign back on the 2nd computer.
I even link my charts across two different computers. So cool!
So I conclude from what I have experienced and as far as I can tell from the TOS manual: my ' Charts, Layout, Custom Studies, and Study Sets' are saved on the TOS servers. My workspace for each computer is saved on the hard drive (I believe).
Hope that helps.