HomeKit bridge: how to customise fan modes in a climate entity?

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Hi :wave::
I have managed to expose my Modbus climate entity to HomeKit via HomeKit bridge. The climate entry has support for fan modes [low, medium, high, top]. When exposed to HomeKit it maps like below:

  1. off and <33: low
  2. 33-67: medium
  3. 67-100: high

I read the document and for fan entity it’s possible to customise the modes, however this fan is embedded in a climate and I have searched for hours but couldn’t find an example. Can somebody give me a hand? Appreciated!