Also, you can distribute your version, of course you can.
Are you sure?
You may Distribute Engine Code (including as modified by you) in Source Code or object code to a third party who is separately licensed by us to use the same version of the Engine Code that you are Distributing.
Any public Distribution of Engine Tools (e.g., intended generally for third parties who are separately licensed by us to use the Engine Code) must take place through a marketplace operated by Epic such as the Unreal Engine Marketplace (e.g., for Distributing a Product’s modding tool or editor to end users) or through a fork of Epic’s GitHub UnrealEngine Network (e.g., for Distributing Source Code).
So, you can only distribute source to people who are specifically licensed by Epic to use the source. That sure doesn't sound anything like "open source" to me.