Heat Control Fibaro, ATAG, HomeKit

Hi there,
I have an ATAG One Zone and 13 Fibaro Heat Controllers HomeKit. I’m not able to configure these according my needs in HomeKit via Apple TV.

Can somebody tell me if Home Assistant can do the following:

IF fibaro_knob_request_temperature > fibaro_knob_measured_temperature THEN atag_one_zone_temparture == fibaro_knob_request_temperature ELSE atag_one_zone_temparture == 15

Do I still need the Apple TV to control the HomeKit devices (also when I am not at home)?

Hope you can help me out…