I don't really understand how this can work properly.What if you're changing a field value that is in the fieldsToMergeOn? Then it won't find the right record.When can you guarantee a non-calculated field is going to be unique? All the field types me...
We built our own view like this in React by creating embed links for all of the views we wanted to have in our sidebar, then have the clicking of the links populate the URL in an iframe.