I cannot find an official website stating which ports of entry are allowed. The closest one with a full table of ports posted on March 2023 includes Chengdu CTU airport (Chengdu Shuangliu International Airport) but not TFU (Chengdu Tianfu International Airport):
City Exit ports Scope of permitted travel Chengdu (Sichuan province) Chengdu Shuangliu International Airport 11 cities in Sichuan: Chengdu, Leshan, Deyang, Suining, Meishan, Ya’an, Ziyang, Neijiang, Zigong, Luzhou, and Yibin Chengdu Shuangliu International Airport
"Some websites" claim that transit through TFU is allowed, but that could be pre-pandemic information.
I'd fly Sichuan Airlines, but I'm not confident I can trust them to provide accurate information if I ask them. I'd like to see an official statement I can print and show before boarding.