Can large cages be good for Chinese hamsters?

[sayaspice]

I am planning on making a DIY cage which is based around a 6 ft (182 cm) display case that I will be getting for cheap in a few weeks. The seller currently does not have the depth measurement of the case (they're out of town) but I will likely replace the glass sides with wooden ones so ideally the cage will be 24 x 72 x 20 in (60 x 182 x 50 cm). This is about 1700 sq in or 10900 sq cm.

I've heard that Syrians are much pickier about cage size than other hamsters species so I'm sure this cage would work for a majority of Syrians and maybe even an active Robo/RCD/WW but I haven't heard much about how Chinese hamsters react to large cages. I do want to clarify that I will be adding in a lot of substrate and many hideouts to avoid as much empty space as possible.

I haven't quite been able to understand my hamster's preferences yet. I have had my Chinese hamster for a month now and it feels like we have gone backwards in taming. For context, he is in a 576 sq in (3640 sq cm) bin cage. He was very skittish the first week which I understand is normal, and then he became very playful, curious, and energetic the second two weeks. He would run for hours in his wheel, and if I put my hand in the cage, he would run in the wheel for 10 seconds, come out and walk across my hand/wrist, explore his cage, then back into the wheel and repeat.

Now I rarely see him in his wheel and he usually runs to hide if I come near his cage. This has been happening for a few days. I know he isn't running in his wheel when I'm asleep because I've been awake for 20+ hrs at a time from insomnia and I never see him or hear him in his wheel even if the lights are off during that time. He does drink water and eat but only for a few minutes at a time and goes back to his hides. I have noticed that he has been burrowing a lot so I assume that is how he uses up his energy.

Would upgrading him to a larger cage make taming even harder? And is there evidence that shows that large cages are not as good for skittish hamsters? I wouldn't want to scare him and I'm afraid I'd be doing more harm than good even if a larger cage hypothetically sounds great. I could see more enrichment and space potentially giving him more fun things to do, but I can also see how so much space could be overwhelming.

Sorry for the long post and thanks to everybody who got this far!