To add a new type into the available types that NodeCanvas recognize, all you have to do, is to open up the Preferred Types Editor window (“Tools/ParadoxNotion/NodeCanvas/Preferred Types Editor”), click the “Add Type” button in that window, then finally search for the type you want (in this case GameObjectFloat) in the popup that will open, and click it.
For example:
[attachment file=”PreferredTypes.png”]
Then once your “GameObjectFloat” type is added, you will be able to add a variable of it in a Blackboard by the “Add Variable” button as normal. If you want to add a variable of type List(GameObjectFloat), then in that “Add Variable” menu, you will find that under “Collections/List(T)/List(GameObjectFloat)”.
Please let me know if that works for you, or if you require more information.