Vensim has some really handy keyboard shortcuts/accelerators. One big set is the number key row for choosing your tools, instead of clicking toolbar buttons.
On macOS v8, there are so many different mouse focus and window focus issues that using the keyboard is basically impossible.
For instance, you have to click in the diagram space to make sure the focus in there. Then press your number to create variable, then maybe press your Equation Editor shortcut. If that doesn't work, click the diagram again to make sure the focus is there. But this means your creating a second variable.
Or, start editing an equation. Click 'Cancel' in that window and try to use a keyboard shortcut to select the Move tool. I've never had that work. Again, you have to click either the toolbar button or click the diagram to move the focus back to the window. Anytime you open a window (Find Variable, or Subscripts window) the focus is lost and keyboard shortcuts don't work.
All efficiencies from using the shortcuts are lost.