I’m working through this synfig tutorial:
At one point the user is directed to alter parameters for a gradient:
Now go to the Parameters Panel (by default it resides in the bottom window), and search for the attribute called Blend Method Parameter. Double-click the entry and select Onto Blende Method Parameter:Onto from the drop-down menu.
I’ve selected the gradient and have the gradient tool active.
Altering the parameters makes no change to the gradient itself.
ie, altering the opacity or the blend method doesn’t make any difference to what can be seen in the canvas.