Yes, we have solutions for both of your questions:
1. To de-duplicate rows when adding them, you can use our Auto-dedupe feature. Enable it by clicking the Auto-dedupe icon at the bottom right of your table, then select "Enable automatic deduplication" and choose the column to dedupe on.
2. To check if a value exists before running a column, you can use our "Lookup, Add, or Update Row with Google Sheets" action. This allows you to search for a specific row in a Google Sheet using a column and value. If no match is found, you can add a new row, or update an existing one if a match exists.
These features should help you manage duplicates and check for existing values efficiently.