Safari adaptative design: is there a way to add screen sizes?

[Jean-Yves_Pochez]

when you activate adaptative design on Safari, you can choose among some view sizes

it there a way to add other screen size at this point ?
thanks.

[Ian_Kennedy]

You can drag the bars at the side of the edges of the “window” it provides to make any size you want. I don’t think you can set any other presets:

Hard to see but they’re just to the left, right and bottom of the display area.