hey guys,
we are also requesting this feature, please 
I have many meetings booked with Latin American customers, where using the informal way is definitely something I would never do if I could personalize the confirmation / reminder emails.
It really does not make a good first impression if I say to someone in a higher position (+ also with 20-30-40 years of work experience), hola + first name, + informal conjugation. I have seen the workflow option video, but I feel it’s just too complicated and not as user friendly as the other great tools of hubspot.
Hope it will be developed soon!