Not for the faint of heart, but for those looking for a project to learn from. You might be able to save a few dollars by buying a Raspberry Pi and RF Transmitter/Receiver to emulate the signals sent from your existing fan. This will allow you to virtually press all of the same buttons that you can on your existing remote. HomeKit access is possible through HomeBridge. Other articles out there can also walk you through wiring your Pi directly to the remote to avoid the need for a transmitter. This works by just wiring the Pi into the existing circuit and allowing it to literally “press” the existing button for you. Listed price is an estimate including a Raspberry Pi starter kit and RF transmitter.