Can the Sanhechang Police Station in Xindu District, Chengdu handle a pass to and from Hong Kong and Macao?

You can't. According to the announcement issued by the Chengdu Public Security Department, as of April 2023, Hong Kong and Macao entry and exit passes cannot be handled at the Sanhechang police station in Xindu District of Chengdu, but only at the Chengdu Public Security Department. The Travel Permit to and from Hong Kong and Macao, commonly known as the Two-way Permit, is a travel document issued by the Exit-Entry Administration of People's Republic of China (PRC) and People's Republic of China (PRC) (namely, the State Exit-Entry Administration, with two brands in one organization) to China mainland residents for private travel to and from Hong Kong or Macao, visiting relatives, engaging in business, training, employment, studying abroad and other non-official activities.