How can I merge 2 Lookup<item> collections

Hi,

I am trying to fill a list box dynamically based on the distinct results from 2 query layer activities. I am using different output columns in each query, so I can't merge the collections directly that come from the queries using Add items because the keys in the resulting key value pairs are different since they are based on the different column names. Now I could create a new collection and copy the contents into it with a new key name, but it would be much easier to just merge the result of both Get Form Element Items From Features activities, because this is exactly what I want: labels should contain all distinct values of query1/columnA and query2/columnB.

Now it seems the AddItems activity does not like Lookup<item> types - is there a way to cast this into an acceptable type?

Thank you,

Helen