Collection Proxy in editor 1 is not in the list of new items. What is the alternative to it?
Are you sure? Can you share a screenshot of the menu?
And if you right click on Outline when editing a game object and select New Component?
There is no option to create a collection proxy file. There would really very little point in creating this type of component as a separate file. Nevertheless, you should create collection proxies inline in your game objects:
And as a sidenote. We really recommend you switching to Editor 2.