Ok, first off all:
putting an SD-Card in there wouldnt really solve the problem, since then the mouse would need ram to load the profile into(also I dont know wth you are doing, I have 11 profiles and still are on 72%), most mice even lack the ability to use macros without the software, not to mention the ability to save more profiles, by managing them a bit intelligent, Roccat for example has 5 profiles(with double the onboard memory), also it's completely normal that you need to recallibrate the sensors, especially since a mouse is under rather heavy accelerations in this case(picking it up, setting it down, and so on)
And if you somehow read into the profile introduction stuff, you would know that you could do this "Button" thing, or at least somehow.
Now making the mouse modular is kind of interesting: its not that easy with a mouse like this without making it even heavier
And pls tell me, which 8 year old kiddie could utilize a mouse like that, yet even pay for one?
And mouses like this wont be allowed in tournaments, since they are way too complicated and allow way too much stuff