The C204/C-ZB-DM204 module is compatible with HomeKit, when used with Philips Hue. The C203 module is currently incompatible with HomeKit, and an upgrade is coming soon.
Yes – this switch is visible to Apple HomeKit when used with Philips Hue. However, please note that this integration is completely dependent on Philips Hue and Apple and beyond our control. HomeKit access could therefore be revoked in the future.