mxtx said on weibo that she based puqi shrine on an actual daoist temple she once visited on weibao mountain in dali, yunnan, called 太子殿 / temple of the crown prince. it was also very old and dilapidated when she first visited, and the donation sign xie lian puts up outside puqi shrine is taken word for word from the donation sign in this temple, which you can see here:

本观危房，诚求善士，捐款修缮，积累功德。 / this temple is on the verge of collapse; we sincerely request that kind benefactors contribute donations for its renovation, and thus accumulate good merits.

she also says in that same weibo post, which you can see in this image, that she was struck with wonder at the size of the huge red camellia tree that stands in the temple. locals say that it's been there for over 400 years, and it still sprouts beautiful red flowers year after year. in her words, "that was when the basic characterisations for tgcf were settled."

thanks to mxtx and tgcf, this temple is no longer that old and dilapidated. if you go there today, you can see a temple filled with all the love every tgcf fan who has ever visited has to give. red thread and tgcf merch fill the entire temple, and the incense fires burn high now that the temple sees regular visitors; in fact, it's often said that this temple now sees the most worshippers/visitors on the entire mountain, rather than being the lonely, overlooked temple it once was.

(screenshot taken from @纪呆呆's douyin)

if you're ever in the area, i highly recommend visiting! the keeper of the temple is always happy to sit down with visitors to share cups of tea and chat about the temple, and he's got a bunch of tgcf stamps too, and there's a lot of tgcf merch in the town at the foot of the mountain