Is “In his later years, undertook massive construction and made errors in appointing regents” true?
attested in history
Records of the Three Kingdoms, Book of Wei, Annals of Emperor Ming notes that in his later years he built palaces, exhausting the people's strength, and on his deathbed mistakenly entrusted his young son to Sima Yi and Cao Shuang.
Cao Rui
In official history, Emperor Ming of Wei was resolute, shrewd, and kept his ministers in check, but in the novel he appears mediocre.