My daughter was on propanolol for her lip hemangioma about 3 1/2 year ago. My wife and I can't remember the exact dosage she was on, but we do know she only took dosages 2 times a day (not sure what has changed in the last couple of years). We did have to check her blood sugar levels too. She remained on it until she was 1 year old.
I totally remember the frustration with spitting up the medication. If it offers any consolation, I wish our daughter had been placed on it earlier. She was only put on it after her lip had enlarged and ulcerated. Once she was on it, the growth stopped.