From what I understand, the router, DECT Phone & IPTV STB belongs to the customer after 1 year. If you cancel within the first year, you will have to return them. But after the 1st year, its yours to keep even if you cancel.

Only the BTU belongs to TM and must be returned if you cancel your service.

Yup, which is why these equipments come with 1-year warranty only. While the TM-owned BTU is given lifetime warranty since its TM-owned. Its just like previously, the telephone set given to all fixed-line phone subscribers are free but TM-owned, and TM shall replace for you anytime if its faulty.