I've had my bed raised at the head by around 8" compared to the foot end for around 6 months now, even during my totally reflux clear perioRAB. The thing with elevating the bed in such a way is that the level of incline brought on by elevating the head end is spread across the entire length of the bed from foot to head. So the elevation difference at the head is 8" compared to the foot and around 4" higher midway down the bed etc. Now the distance between your waist/stomach area and neck/throat region is much shorter, only taking up maybe 30% of the length of the bed. This is the important region of your body in regarRAB to reflux moments when laying down in bed. So even with the bed on the incline with blocks/bricks/books etc under the head sitting say 8" higher than the foot, the effect is reduced for your neck to stomach region as that length is far shorter than the entire length of the bed. So therefore you're not utilising the full incline the bed produces, but only about 30% of it. Basically, your neck/throat region isn't 8" higher than your stomach region, it's maybe 2-3" higher at most.
Now with wedges, which I bought one of yesterday, they produce the incline in that immediate area of the top half of your torso, not across the full length of the bed, providing a much higher incline from head to waist. I have lowered my bed right back down to where it used to be, with the base sitting just 1-2" off the floor at both head and foot and have placed the wedge under the mattress/top of the base at the head end. It creates a much more inclined surface for the important region of the body as it focuses primarily on that, rather than spreading the incline across a much further distance. And with the addition of some good pillows you can raise even higher at the shoulder region for more incline as long as it's comfortable. I tried using the pillows to incline me when using the whole bed inclined but found I would slide down at times and wake in not the best state. But with the bed flat in the lower half now that allows me not to slide as my legs and feet have no incline now to slide down as the flat surface there curtails that and keeps me raised in my upper half. I did this last night and has no real reflux at all compared to bad night the night before. Bed time comes around in another 9hrs or so and hoping it will be as good or hopefully even better.