✕The night on the Longji terraces+
It was in, and it is out — and with it, the trip’s fourteenth day. The reasons, in order: in mid-September the terraces are green with the first yellows (full gold arrives in the last week of the month, and the harvest is held back to Oct 24–Nov 2); sunrise is a fog lottery; and the place is expensive in hours — two half-days on mountain roads, luggage split in two and a basic guesthouse in between. What is lost is real: the terraces empty from ~16:00 to ~11:00, the only way to see them without day tours. If anyone goes back, go in the last week of September or in October, and sleep in Tiantouzhai (Dazhai). In its place the trip gains an extra half-morning in Yangshuo and a whole afternoon in Guilin, and it frees up Wednesday the 23rd to fly to Bangkok.
✕The big Li River cruise+
Replaced by the Xingping raft. The boat takes 4–5 hours and spends its final stretch on flat scenery (lunch is served exactly there); the raft covers the star section, costs a third and gives back a good half-day. The only thing lost: sailing into Yangshuo.
✕Wuyuan: Huangling and Wunvzhou+
It was in, with one night, and it dropped out mid-trip to reach Shanghai a day earlier. Of everything left between Guilin and Shanghai it had the least name: Huangling is a drying-rack village rebuilt as a park (and in September still far from its October photo), Wunvzhou is a 2022 stage set, and the real Huizhou villages, Hongcun and Xidi, stay in the plan. The issued T3 does not change: at Shangrao you carry on to Huangshan North instead of getting off at Wuyuan. What you gain is a whole Sunday in Pudong.
✕Wangxian Valley+
Out, to slow the pace. The long train to Shangrao happens with or without it (Shangrao is the obligatory junction towards Wuyuan and Huangshan), so it only cost a night and two hours of driving — but it is a scenic reconstruction, not a thousand-year-old town. Hongcun and Xidi cover the authentic part. Re-examined for the day-7 evening: arriving in Shangrao at 15:09 with suitcases and Tunxi still ahead, it does not fit.
✕Sanqingshan and Gexian Village+
The other two names around Shangrao. Sanqingshan (UNESCO, granite pinnacles with cliff-hung walkways) is genuinely serious — but it needs a full day that does not exist, and it is "Huangshan in miniature" when you climb the real one 48 hours later. Gexian Village is another fabricated Taoist village with lights: 90% redundant with what the trip already has, and worse placed. Neither is worth breaking the itinerary for, and both duplicate something you already have.
✕The night on the Huangshan summit+
Sunrise over the sea of clouds is spectacular, but it is the opposite of resting: a spartan hotel, a 4:30 wake-up and a backpack on your shoulders. If you ever come back with more margin, it is the first thing to reclaim.
✕Chengdu+
It repeats Chongqing's role. The only unrepeatable thing is the pandas, and it costs two days.
✕Zhangjiajie and Fenghuang+
The alternative route. More spectacular in one hit and with the best old town in China, but the connection towards Huangshan forces a transfer in Changsha with only 4 trains a day.
✕Enshi+
Well connected to Chongqing (2 h 17), but it is a car destination: an hour and a half to the Grand Canyon, three hours to Pingshan. And heading east it is a dead end.
✕Shanghai's water towns+
Zhujiajiao, Nanxun, Xitang: not included by default. The slot they had was the free Tuesday the 22nd, and Disney (Monday) took it, with the city itself moving to Tuesday. Zhujiajiao (~1 h each way, metro line 17) stays the natural outing if anyone comes back.
✕Phuket, Krabi and the Andaman Sea+
Thailand’s postcard beaches are on the other coast, and they are out for two reasons rather than one. First: another hour of flying from Bangkok plus transfers, which out of five nights eats a whole one. Second, and decisive: September is the Andaman’s worst month — peak southwest monsoon, heavy swell, red flags and long runs of rain. The Gulf of Thailand, where Samet is, holds up far better on those dates. If you ever go back for Phuket or Krabi, go between November and April.
✕Koh Chang and Koh Kood+
Objectively prettier than Samet — Koh Kood is among the best islands in the country — but they are 5–6 hours by car plus a ferry from Bangkok, and in Koh Kood’s case the boat does not run continuously. With three nights, two would go on road and water. Samet wins on one thing only, and it is the one that matters here: it is three hours away, and in the least rainy corner of the gulf at that.
✕Pattaya and Hua Hin+
Bangkok’s two “easy” beaches, both ruled out for the same reason: the water. Hua Hin has seven kilometres of sand and good hotels, but the inner-gulf sea is a brownish green and not what you want after thirteen days of cities. Pattaya is ninety minutes away with a mediocre beach and an atmosphere that is not this one; its good cove, Ko Larn, fills with day trips and its last ferry leaves at 18:30, so on the 23rd you would not have made it.
✕Bangkok’s old town+
The Grand Palace, Wat Pho and Wat Arun are not in the day-17 plan — they are an alternative inside that day, and the choice is yours. The reason they are not the default: with a single full day, the old town swallows all of it (it is far from the metro, you get there by boat and taxi, and the Palace closes at 15:30), and it costs you Chatuchak, which only opens at weekends and happens to fall on your Sunday. There are temples on any trip to Thailand; that market, on that day, there is not.
✕Ayutthaya+
The old capital, with its ruined temples and the Buddha head caught in the tree roots. It is ninety minutes from Bangkok by train and a full-day outing — and a full day is exactly what there is not. It waits for the trip where Thailand is the destination rather than the epilogue.