Can I remove the warning for unknown property in the column?... YES

Adding custom properties to your own colDefs

ag-Grid allows for adding your own custom properties to your own columns, but you might find that you get a warning in the console if you do so.

This warning is there to help users spot misspells in their source code but it can be disabled.

The warning can be disable by setting the following property:

gridOptions.suppressPropertyNamesCheck = true

https://www.ag-grid.com/javascript-grid-properties/

suppressPropertyNamesCheck	Disables showing a warning message in the console if using a gridOptions or colDef property that doesn't exist.