Bro, they didn't create the dimension. The universe couldn't handle their power, they broke the barriers of reality and ended up in another dimension. If you really got "they created the dimension" out of that, I don't know what to tell you. Because that just flat out isn't true.
Genuinely, why is this a debate? The universe couldn't handle their power, so they broke into an alternate dimension, they then broke several more dimensions, resulting in the reality collapsing. That's Low 2-C, that's it, end of story. You don't need explicit statements of size to know that destroying a dimension. That they were brought to Specifically because their actual universe couldn't contain their power. Then proceeding to Collapse the reality of that dimension, is anything less than Low 2-C. At this point, Y'all are just arguing semantics.