Golden Superman was stronger even than Silver Age Superman, at least in his higher-dimensional form.
Just like Ke Chen now, he had absorbed all of Golden Superman's power, along with all the knowledge of the DC universe. A Kryptonian's brain was also incredibly powerful, as shown in its ability to absorb, comprehend, and process knowledge. Ke Chen might not have been the smartest person in the universe, but he was undoubtedly the most knowledgeable.
In truth, Golden Superman and Silver Age Superman were not fundamentally all that different. The difference was that Golden Superman had already become a higher-dimensional being. As for power, Silver Age Superman was already strong enough.
Silver Age Superman could impose all sorts of abilities upon himself, while Golden Superman had reached the level of Creation.
For example, he could reshape Krypton and resurrect Lois Lane in a fifth-dimensional form.
In other words, as long as Ke Chen collected fragments of Krypton, he could easily restore Krypton. This was the means of Creation, no weaker than The One Above All and Lucifer had been back then.
There were only a handful of people in the entire universe with such means of Creation. Ke Chen himself possessed the abilities of a Creator, and now, coupled with Golden Superman's higher-dimensional Creation, the two complemented each other perfectly.
Higher dimensions could be compared to a higher level of life. While they did not bring an outrageously massive increase in power, the life form itself had changed.
Ke Chen was quite satisfied with this. If he wanted to go any further, he would likely have to reach forms such as Thought Robot Superman or Mind Superman.
But this was not the only way he could grow stronger. To be honest, Ke Chen no longer had much demand for greater power.