I can see how someone that is so analytical can get caught up in overthinking and second guessing but you made the right choice. My son just turned 8 and is in a similar level skate. I see kids in all levels of skates at this age and there is no correlation to skating ability. For my son, i would rather stay in a mid-tier boot for all the reasons that have been outlined before, buy on sale and keep him in a skate that fits well rather than think he needs top of the line and try to buy so he has room to grow and keep him in it too long because it is so expensive to get new ones.
I can’t see the tongue being a mod that is worth it, steel, maybe, I will let others chime in.