That's way beyond what the IPC and UPC require, so I looked up those provisions. UPC says
https://up.codes/viewer/washington/upc-2021/chapter/3/general-regulations#313.3
Cast Iron Hubless -- Shielded Couplings -- Every other joint, unless over 4 feet then support each joint
1 Support adjacent to joint, not to exceed 18 inches (457 mm).
2 Brace not to exceed 40 foot (12 192 mm) intervals to prevent horizontal movement.
3 Support at each horizontal branch connection.
IPC says
https://up.codes/viewer/pennsylvania/ipc-2018/chapter/3/general-regulations#308.5
Cast Iron Pipe -- Maximum Horizontal Support Spacing 5'
a The maximum horizontal spacing of cast-iron pipe hangers shall be increased to 10 feet where 10-foot lengths of pipe are installed.
Cheers, Wayne