Allow the Fit to Window button in ModelBuilder to actually fit to the window instead of zooming to 95%. Seems to do the opposite. Then allow MB to save this setting when 'save' is clicked so when the model is opened again the zoom level is saved with it. Make it like ArcMap behavior, please.
ModelBuilderFitToWindow1.jpg = zoomed in by scroll button on mouse
ModelBuilderFitToWindow2.jpg = zoomed to 95% when fit to window is selected.