ShowTextFitHint suggestion: maybe it is necessary to show the hint below the editable cell (with buttons) or add option to control hint coordinates?
It is inconvenient to work with Hint in a cell with a drop-down list or a button - the pop-up window closes the buttons.
Under Windows, a mouse click "breaks through" this hint to hidden button, but in an application under Wine (Linux) the hint blocks access to the button.