Ctrl(Cmd on MAC) + Left(Mouse)Click on the panel.
Ctrl(Cmd on MAC) + Shift + Left(Mouse)Click on the panel.
If this operation is successful, it will say so in the info line at the bottom of the SV window.
First, make sure that the Fit panel has data and a model selected.
Ctrl(Cmd on MAC) + Shift + + Alt + Right(Mouse)Click on the panel.
Then, set up the value in the dialog panel.
If this operation is successful, the new ftol value will be displayed in the info line at the bottom of the SV window.