Kai Tak Development Area will provide over 13km of GreenWay network (shared use by pedestrians and cyclist), which will be completed in phases (by nearby development project usually). The first phase will be completed by 2023, second phase will be completed beyond 2025, while some sections are subject to future development and study.

“MULTI-MODAL” EFLS , GreenWay Network proposed by Government CEDD in 2021

Conceptual Master Plan 6.0 proposed by EKEO in January 2022
Note that the GreenWay is not seamlessly connected. Cyclist is required to dismount in some sections.

From Kwun Tong District Council Document in Sep 2017, CEDD and LCSD mentioned that due to environment limitation, cyclist is required to dismount to push the bicycle.
Integrated from various sources, the GreenWay network is drawn in the following map. Note that some path are still not confirmed and just from deduction.
For clearer elaboration, the GreenWay network sections are introduced in groups below:
Kai Tak Station Square Phase 1 is already opened in Dec 2021. Phase 2 will be completed in 2022 tentatively. A section intersects with covered walkway, dismount is required.
Kai Tak Sports Park will be completed in the second half of 2023. Part of GreenWay is constructed by adjacent Hotel / Office (H/O) site NKIL 6607. This H/O POS (Public Open Space) will be completed in 2022.
This section connects Kai Tak Station Square Phase 2 to Kai Tak Sports Park, which is inside future Sung Wong Toi Park Site. Construction of Sung Wong Toi Park will not start soon as other development projects are occupying the land as temporary site, while this GreenWay is mentioned to be completed in 2023.
Riverside of Kai Tak River will provide GreenWay. Kai Tak River Opening Space (North of Shing Kai Road) is still designing, the GreenWay will connect to Kai Tak Station Square. A pedestrian subway will connect Olympic Avenue (near Kai Tak River) and San Po Kong (outside Lee Kau Yan Memorial School), while it is still planning.
GreenWay in the south of Shing Kai Road consists of three parts. The first part is inside Additional District Cooling System (DCS) Plant (under construction). The second part will be under road outside Kai Tak Tunnel (planning). The third parts will be under roads of Central Kowloon Route (CKR), it is under construction by CKR and it will connect GreenWay of former South Apron and the North of former Runway.