I don't have answers, nor direct experience, but thought I'd offer some suggestions for further inquiry, based on my own long history with other medical devices. First, perhaps someone has already done this, but I didn't see it mentioned: the accompanying literature (product guides and package inserts for things like test strips - this may even be online) generally without fail include contraindications and limitations of use. It may not specifically address thalassemia but perhaps it will indirectly (anemia, hematocrit, etc). Now, this will still likely be generalized and not definitive for any given patient. But in my experience, companies that make medical devices will research and do almost anything you need when you give them a call and tell them you are considering acquiring their device, but have an issue that needs to be addressed. For one device of mine, a company was unable to address my concern through research to my satisfaction, but offered me a training "loaner" device so that I could verify it would meet my needs. It did and only then did I commit to purchase. I've dealt with different companies, sure, so could be wrong in this instance, but might be worth a shot...
Sounds like good practical advice - thanks!
pem