If we have 0°C and rain just before pushback and the rain just quits because the cloud moved, there is no reason to entirely skip de-/anti-icing.
Since deicing is entirely skippable, the rules for the options should be far less strict.
by checking the quantity of ice variable.
Won't help in the above scenario either. For icing not just the current conditions are relevant but also those in the past *and* in the future. If you know that temperature is dropping and expect a departure delay, you'll need anti-icing treatment even though the conditions during taxi might be just good enough.
Your criteria basically is based on when de-/anti-icing is clearly required, but there is a big grey area where the flight crew's decision based on experience and conditions, traffic and predictions do matter and can result in treatment.
Please allow us to enable an option that de-/anti-icing is always available so we can decide ourselves when we consider it to be required or raise the 0°C limit to +5°C to have the option available in more cases even if the other rules don't apply.
While some users might like this to be decided for them, obviously some don't since there is no workaround if GSX just decides to not show the option.
