Hi. Assuming this is possible I would love to see it implemented. I ran into an issue where my window wasn't resizing. I ensured the application was running and at the front, but no dice.
Adding a random time as a workaround isn't ideal (esp if you intend to use on different computers).
I guess in some cases a bunch of conditionals would work, but seems like wanting an app fully loaded before carrying out the next action would be common enough to warrant a baked-in solution if possible (I realise it may not be).
There is a workaround involving waiting for a specific menu item within the app to load (some load later than others, especially ones that connect to servers), but again this doesn't work for all menu items and in some cases not at all.