I have only recently read through this thread and have a few comments to make with respect to your opening post…
It is helpful to understand the ecological circumstances of juvenile snake in nature. They are on the menu of a host of other animals, including large frogs, larger snakes and lizards, predatory birds (from Butcher birds up to raptors) and medium sized to larger native/feral carnivores and omnivores. Their challenge is to warm up and find a meal, without becoming a meal themselves. So in between basking and hunting, they seek a security refuge where they can coil up and conserve body heat and also have a measure of protection from potential predators. Translating this into captive requirements, hides should be snug fitting with minimal space for anything else to enter. Where the snake can feel the roof of the hide plus a significant amount of the sides, then it will feel most secure.
Hides do NOT need to be shop bought. There are lots of cardboard packets that can be found in the house that make excellent hides, often better than those commercially sold. For small species hatchlings, hides the size of jelly, medicine or band aid packets, with a square section of the end removed, are appropriate. For larger hatchlings and developing juveniles, cardboard packets such muesli bars (x5), pack of soup or ‘Lean Cuisine’ type packets, with the same sort of hole (i.e. just big enough for the snake to slide freely through) are excellent. Another very effective and cheap hide is cardboard toilet rolls. Depending on the size of the snake, these can be joined, two or three together, to make artificial hollow branches. A length of sticky tape around the adjoining ends is all that is required to hold them firmly together.
The existing hide in your enclosure appears far too large for the size of the snake. If it were me, I would start by making up four or five toilet roll ‘hollow branches’, placed at roughly even spacing from one end to the other of the enclosure. Then as opportunity presents itself, I would add some cardboard box hides of appropriate size. Then observe the snake at various times and determine which style of hide it prefers. Ultimately the aim for me would be to would be to provide probably five of the preferred hides for an enclosure that size, that were evenly spaced across the temperature gradient.