Wow, 6oz is a big feed for a 9 weeker!!! Have you tried a smaller feed followed by a dummy? Perhaps she just wants to suck rather than is still hungry, if you follow that?
Has she had an examination to watch her swallow (where they take xrays as she drinks a special drink)? This tells you if her "valve" at the top of her stomach is closing, if her stomach empties quickly or slowly. Emfamil AR stays down because it is thickened (hence the big hole in the nipple) I can't remember if it is with rice or corn starch.
Ths thing with positioning is that whilst keeping her upright for half an hour or so helps to keep her last feed down in the short term, when a baby with reflux lies down (particularly on thier back, even reclining)) the contents of thier stomach washes back up the oesophagus, the stomach acid burns (remember the heart burn you had during pregnancy?) so, even if they are not actually vomiting they are in pain, hence the screaming. Carrying her in a sling will make her much more comfortable as it will reduce this burning feeling in her throat/chest.
Have they checked to see if cows milk is a factor? 50% of babies with reflux show an improvement or even a complete cessation of symptoms (like in my DD2's case) when cows milk is removed from thier diet. Within a week or so of me taking dairy out of my diet my snuffley, colicky, green pooing, dry skinned screaming baby was trasnformed into a content smooth skinned cherub. It's such a relatively simple thing to do, and it can have such amazing results, its certainly worth trying. A formula that is free from cows milk or getting her back to the breast may be all you need to do to make both your lives so much easier.