Hi splat haven't read all the posts yet, but there was a thread on this a few weeks ago.
My youngest who is now 3, had reflux and i had a lovely health visitor, who, at the time had heard about a new baby milk for babies with reflux.
It's called SMA STAYDOWN.
Comes in a tin with a purple/lilac lid.
The milk has a thicker consistency.
Do not use it with Gaviscon as it'll be too thick for baby.
We were also advised to give smaller more frequent feeds, as her tummy wouldn't be able to take much.
Also, with reflux babies, you have to keep them as upright as you can, for up to an hour after each feed!!!!!!
I found the best way was to sit her in her baby chair.
Or if placing in moses basket/cot then i'd put a blanket under the head of the mattress to keep the head raised higher than the stomach.
Hope this helps.
Good luck as i really know how much extra work you'll have.