Loxone heating in Homekit

Hi, I am trying to setup the Loxone heating controller in openhab to be visible from HomeKit.
The items needed by HomeKit are different, but the obstacle I cannot solve is that the target temperature in Loxone is a difference to the current one. This is a read/write channel but the offset I have to set is another channel in order to get a read/write channel with the target temperature for HomeKit.

Has anyone solved this? Either being able to set a “Number” item as the addition of two channels so it is read/write or maybe to follow a complete other approach?

The only thing I can think of is to modify the the Loxone binding to transform this channel into the absolute one instead of the offset. I have done these things in the past, but then when there is an update of the binding it is a nightmare to keep up.

probably you need a second set of items just for homekit and rules to map between homekit and loxone items (and calculate offset)

I thought of that, but in my house every room gets independent climate controller (12 in total). I am looking for a clean solution or the configuration will get too complex.