Yes, you can do this by creating a single relation to the row in question, and then use a delete row action through that relation. If you take a look at my custom forms concept app, I use this technique to limit the number of rows (every time a row is added, one is removed).
I’m not familiar with the template, but just in general - if you wanted to retain row owners in your User Profiles, what you would need to do is create a read-only view of your user profiles table with a minimal set of columns, and refer to this with your 1:1 chat. This is easy to do if you are using a Google Spreadsheet as a data source, otherwise it could be a challenge.