Harry, leaving threads would be up to their importer; our data is kept logically in a database, all they'd have to do is convert it.
As for an integration; it is possible however you'd have to do several things:
1. install both products
2. hijack the registration routine of jamoola, have it also populate the UBB.Threads database.
3. hijack the login routine of jamoola, have it also set the UBB.Threads cookie upon login.
4. hijack the logout routine of jamoola, have it also unset the UBB.Threads cookie.
5. insert a link to your threads install within the menu system of your jamoola install.
