Using item save glitch, it’s possible to get every cube in the game, including any in a_00 and inside the dispensers. It requires doing 00-04 twice, and it requires you to quit the game a few times (I don’t know how that works in relation to the rules), though.
I’m a bit late to respond to this but I think Nano showed me a video of something like this before with a similar idea. It’s pretty cool but at the time I thought it was tedious so I didn’t end up doing it. I would be fine with people restarting their games for item save glitch, as long as you don’t start a run with it activated.
Having done a ‘run’ of this, I can say that it is tedious, but the thing that I find most awkward about it is creating a hard save in 04 and then reloading it. Obviously, in the context of rules this is fine as the save was created within the run. I just find it weird because you open the console a few times. This could be avoided by having binds to save/load this, but I still think it’s awkward to be jumping around the game, from 04 to 00, back to 04 etc.