Han Xiao opened his Profession tree for a look. The current maxed Lv.5 knowledge did not reach the required thirty to give him the title of [Erudite], but he was close to it, just requiring him to raise a few lower-tiered knowledges. The problem was having an Ultimate Knowledge of each of the three branches maxed out.
Another important source for potential points would be to reach max level for his skills, but the upgrade cost would increase exponentially with the character level and sum of all skill levels. For a non-related branch Ultimate Knowledge, it would require roughly 120 Potential Points to upgrade from Lv.0 to Lv.5.
It was also impractical for Han Xiao to suppress his level. Even with all the experience he had saved up currently, it would not be enough to bring his Ultimate Knowledge to max level.