The good thing I found with the EZ foam pillow is that it is shaped so the sides slope downwards towards you - so the babies roll the correct way and they are less likely to fall off.
I used the pillow on a feeding chair at my mum's house, but to be honest it's not great - not because the pillow doesn't fit, but you need to think of the logistics of feeding two at the same time.
Unless there will always be someone there to pass you the second baby and take away the second baby after feeding, a feeding chair doesn't work. You'll need a place to put baby 2 while you position baby 1, and then you need to be able to reach baby 2 (without tipping baby 1 off!) and put them on the cushion too. Try it with a couple of teddies or something and you'll get the idea of the problem! I guess if you could find something a suitable height to put next to the feeding chair that you could 'park' a baby on then that would be work.
For me, I fed (always sitting up and never lying down) on a sofa, purely because it meant there was a safe place to 'park' baby 2 while I sorted baby 1 out. We used a v-pillow as the 'parking spot' for baby 2. This worked until the babies were 6 months or so and started rolling, after that I fed them separately.
It went
Put on EZ pillow (it clips on so you can 'wear' it and then pick up the baby
Put Baby 2 in 'parking spot'
Pick up Baby 1
Sit down on feeding sofa next to 'parking spot'
Position Baby 1 on far side of 'parking spot'
Then pick up Baby 2 and position them.