I cannot think of any other use of a Get{Entity}ForUpdate, other than assigning to some attributes and then updating the entity. That requires, at least, three nodes.
My proposal is, when you drag a Get{Entity}ForUpdate to an action flow, besides creating that node, it would automatically create an empty assign node, and an Update{Entity} node with the Source referring the Get{Entity}ForUpdate.
If it is dragged to a connector, then link the incoming connector to the Get{Entity}ForUpdate, and the outgoing connector to the Update<Entity>.