In this question, I asked how to have Siri specifically send an SMS message to a person who does not have an SMS-capable iOS device registered with Apple, but does have iMessage on e.g. an iPad.
The answer was to say e.g. "Text Alice on mobile I'll be there soon," since "Text Alice" or even "SMS Alice" would not force Siri to use any specific mechanism.
However, we could not discover what magic word one could use in place of "mobile" to force the opposite effect: sending an iMessage instead of an SMS. Words I've tried include:
All of the above result in a message containing the magic word, e.g. "Text Alice on iMessage I'll be there soon" results simply in a message reading "On iMessage I'll be there soon."
Does anyone know what the magic word is for iMessage, if there is one? Such a magic word would allow me to use Siri to send my choice of an SMS or an iMessage to Alice, since Alice carries both a non-Apple mobile phone and an iPad, though she does not necessarily have both on her or online at any given time.