Hi!
Thank you for your suggestion, it is similar to what I have offered as one of the workarounds for users... to basically search individual features and go that route. I also have layers that are already tied to the locator (in this case parcel layers - parcel locator) and have suggested setting an SQL filter to achieve a similar result.
However, the issue is that some of our users have lists of parcels of say 20 or more, which begins to make it difficult to search for individual parcels and/or filter for multiple parcels.
In an ideal world, users would be able to upload their CSV tables using the Add Data widget and then select an option to "add to map" based on a list of locators that we select on our end. Fairly similar to the workflow when uploading a CSV file onto ArcGIS Online, or workflows seen in other applications such as WebAB/GeoCortex.