Just getting caught up on your thread... my daughter's been having lots of headache issues, had been interested in seeing what you had found (even though my daughter is no longer a child! )
But, in reading... just want to add a couple of things...
Re paying for FC privately - as far as I know, it's not 'illegal' in Canada. I'd once asked S's GI if he could run the test. He told us it wasn't covered (this was quite a while back) and, in S's case, he didn't think it would be useful. But, he did say if I wanted one, he was happy to order it but that we would need to pay (he thought it was approx. $200).
And, re the formula, yes, we had it covered for approx. 2 years (both during exclusive and supplemental periods). We were in a different situation than you but, perhaps, you can try... How it came about with us...
S was inpatient at Sick Kids and was diagnosed. His treatment was exclusive EN for six weeks and the planned maintenance was going to be supplemental EN going forward. While at the hospital, they connected us with CCAC (they've recently changed names but it was Community Care Access Centre and you should be able to find the agency if you google this name). The hospital told us CCAC would cover the formula (and equipment for 3 mos) as long as the formula was prescribed. The nurse did say sometimes CCAC extended the coverage... anyway, the three months came and went and CCAC continued to cover. I did have to call the agency a couple of times over the two years to have their coverage renewed but there was never a problem... they said they would cover as long as there was a prescription (and as long as the government didn't change the rules). The only condition was that we had to have a nurse visit on a monthly basis (if we refused the nurse, they would discontinue coverage of the formula :ybatty: - crazy as we didn't need the nurse and resources were being unnecessarily spent on that!) During this time period, they also covered the rental of the pump, all NG tubes, bags, etc.
I'm not sure how you'd go about initiating this as our was initiated by the hospital but, perhaps, your GI or ped could help??