An asset instance in Dungeondraft is under-the-hood a Node of various types in Godot but with a unique id assigned. Any instance must be modified with care, verifying that the modifications do not cause bugs.
Best practice is to modify an asset instance through a given function from a Tool rather than accessing its properties directly, with the exception of its transform (ie. position, rotation, and scale).
All asset instances are also Godot Node2Ds and therefore, you will be able to access the functionality here in the Godot docs: Node2D
Get the unique ID assigned by Dungeondraft.