Hi Patrick,
If I'm understanding your use-case correctly, I think this is a fair question to ask.
What I would recommend trying is rather than do a call to utag.view() or utag.link() alone, do this instead:
//note the first line is referencing utag.data, not utag_data
utag.data = {};
utag.view ( { name : "data1" } );
Where the value being passed to utag.view() directly are all the values you'd like to use, rather than using utag_data for subsequent calls. This means that if you do want to use a pre-existing value, you'd need to alter this approach. There are some other minor caveats we'd be happy to work through with this if so if you'd like assistance, please contact your AM if you'd need more detailed assistance with this.