I can order most big name foods online, but I've never seen YAZC before. Where do you find the carb % for dry foods if it's not listed on the particular website? I checked on the Nature's Variety and Orijen sites, but it isn't listed, and most of the food lists showing low carb foods are only for wet food. I'd prefer to stick with Instinct, mainly because it's something I know they will both eat (both of them are so picky...), but I want to know the carb% before ordering another bag. EVO Cat and Kitten Turkey and Chicken would be one to fall back on if it turns out Instinct is too high.
As for the vet, the vet my mom uses in Canada refused to discuss Bangwol's labs without seeing him first. There aren't a lot of decent vets near me, and some don't even treat cats (rather, don't know how to) He is doing okay right now, so I will wait it out and go with him for his check up on Friday night or Saturday morning with the same vet. I will mention everything that has been said thus far in the conversation about his anemia, and hopefully will have my glucose monitor by then to ask about home testing. I will ask for complete blood work to be done, since he didn't check anything regarding kidneys for a while... If I don't get the results or answers I need, I have the business card of vet in that area who treats cats, so I can try there too.
You will have to leave a little bit of food out for him then while you're at work, obviously. Hopefully his BG will stay in the normal range without insulin but if you can't get low carb dry food, keep testing his BG twice a day, before he eats (as long as he hasn't had food for two hours before the test since food can influence the numbers). Not ideal if he has to eat higher carbs but he needs to eat. 
