Does Laryngomalacia effect weight gain after 1 year of age?

I have an 18 month old who’s weight gain began to slow down at about 4 to 6 months of age.  He was born full term…my third c-section.  He weighed 7 lbs 14 oz at birth and was 20 inches long.  At his two week check-up his pediatrician diagnosed stridor and sent us to an ENT soon after.  The ENT scoped him and determined he suffered from a soft larynx (laryngomalacia).  His epiglottis was curved in a tight “C” shape and upon inspiration he noticed it would close up tighter causing the noisy breathing.  Doc prescribed Prevacid because he believed infants with this condition always suffer from reflux.  My son never had symptoms of reflux.  He rarely spit up and was never fussy.  Furthermore, he hadn’t had any problems gaining weight.  He started out in the 50th percentile for weight & height and maintained that until his four-month check-up when he started to slip on the scales to 10-25%. Coincidentally, I also had to stop breast feeding at this point because I was no longer producing enough milk, and our son had very little appetite for formula. At six months his weight slipped again to 3%.  His pediatrician recommended a gastroenterologist. The GI doc performed a full work-up and decided there wasn’t any medical reason for his slowed weight gain.  My son maintained his weight at 3%.  In the meantime, developmentally he was fine.  To quote his pediatrician, he was almost perfect were it not for his weight.  However, at his fifteen-month check-up his weight fell below 3% prompting the GI doc to want to perform an EGD.  I think it’s important to note here that he fell ill shortly before this check-up.  He suffered a viral infection that consequently killed his appetite, which was never much to begin with…hence the problem with weight gain.  At the time, we chose to hold off on the EGD because we felt strongly that the slip in weight was a result of his recent illness.  Now we arrive at his eighteen-month check-up and he is still below 3% in weight.  And we are faced with moving forward with the EGD his GI wants to perform, have the ENT look at him again, or do nothing and hope that this is just the growth curve his body has chosen to follow.  We are leaning towards the latter since developmentally, he’s fine.  But naturally we’re hesitant because on one hand we have two medical professionals who are concerned about his slow weight gain, and us on the other hand who feel that as long as his development is on track there shouldn’t be a cause for concern. So who’s right?  We would very much like to have another pediatrician review our son’s history and hopefully help us come to a decision on which way to proceed.