Setting up Recuperator to control via HomeKit bridge

I’ve been able to set up an ESP32 device to control my recuperator via modbus (thesslagreen.yaml -
I got it to a point where I can control some of the parameters (via selects visible in the code), but the device type/class isn’t used properly in HA and I can’t set it. When exposed via homekit bridge, it is displayed as a series of four switches, while what I’d like to have is a switch (especially name: “${device_description} tryb pracy”) that can change between 4 states.
It’s basically a big fan that can switch between few modes, and that would probably be the most suitable class that HomeKit offers. How can I do it?