If you are using the layout editor to place your instances, I think you will have to set them manually. Set them as you go, you'll have to go through each object to place them eventually anyway.
In the event that you really do have 1000 objects to place with unique instance variables, it is probably a good idea to set up a system with events to create them dynamically.
You can use placeholder objects and replace them on layout start and set all the properties of the object and its variables.
Or you could use a simple array to store the data - each object would get an x, y, angle, size, instance variable ect, then loop through the array to create all your objects.