That's really great news, make sure to let me know when the tests are scheduled and how it goes. Your pediatrician may not think that it sounds like he has dysphagia, but as a professional who works with this on a regular basis, I wouldn't have told you it sounded like dysphagia if it didn't! I'm not a huge fan of thickening with cereal, mainly because you can't get cereal through a regular nipple meaning you have to make them larger or use cross-cuts. If you do this, you're kind of making the whole point of thickening moot. To thicken and then make the larger nipple basically like leaving it thin liquid and staying with what you have. You also cannot get cereal to thicken the liquid uniformly. You will have some thickened formula and some runny. That's my opinion on that.
As for you question on Simply Thick, I've had a nutritionist/pharmacist with the Ohio State University look into if it blocks nutrient absorption. Her reply was that over a huge period of time it may deplete a small amount of a few nutrients (I forget which ones off the top of my head, but I believe there were 3), but the benefits of unsing the thickener far outweighed the the minimal amount of nutrient absorption that may or may not occur. The only other option is to try feeding in different positions and giving frequent breaks from the bottle during the feed (not meaning let him eat 2 oz. and then 20 minutes later take 2 more and so on, what I mean is let him suck 10 times, more or less, and then take the bottle out and keep doing this throughout the feed). That's the other option, well...........or try side-lying or sitting completely upright with the frequent breaks(sorry, I'm rambling).
Glad to hear things are going well. Just using the thickener alone will also decrease reflux and keep things down. Once I started thickening Luke's formula, not only did the swallowing problem disappear, so did his reflux!
Keep me informed!