This might help you with figuring out Cell Size and Cell Border.
https://www.dropbox.com/s/km7j3r9kci5zh ... .capx?dl=0
It draws the cells & the borders. Change the property's for the path finding behavior. Change that one global variable. And run it.
You might find it surprising to experiment with some values.
Also, what this little experiment will teach you. The curve of the path is not depending on Cell Size and Cell Border. It depends on the way that it is moving over the path. And the only 2 properties you have at this moment to change the way that it moves is Speed and Rotate speed. Try some combinations.
So, to stop it from cutting the corners (in tight grids) and have a natural way of moving, we need to take care of the moving our self.
One of many ways, using a 3th party plugin :
https://www.dropbox.com/s/10sw1nuam5lcs ... .capx?dl=0