The original chassis is definitely made on Aima's factories for sure. There are tons of kickscooters similar to Xiaomi's, and different only in bodywork, and it's rumoured that OEM is Aima. This is true for a lion share of all scooter sharing companies.

Liubike is a scooter sharing company from Zhejiang. They originally developed a sharing solution based on Xiaomi kick scooters, but later switched to proper electric mopeds. Liubike, then resold the OEM "platform solution" to other companies, but still runs an own sharing business in smaller towns in Zhejiang.