[Alquanto]

I would like to suggest an alternative implementation of the pinch-zoom option that might be more usable.

If OmniGraffle had an application-level setting for display zoom this could be controlled by the trackpad commands. This would affect only the display and not the document data (in contrast, the current zoom either modifies the selection or the canvas. Canvas currently appears to modify the the currently selected canvas - something which I have always found odd given that the useful zoom is more usually a function of the physical display that you are using rather than the document data itself).

Sensitivity to accidental changes could be reduced by ignoring small changes. ie: only change the display zoom if the trackpad pinch exceeds a certain amount.

-- Mark