Just wondering if changing all the ints representing midi values throughout my code to uint8 would make any real difference? Is it considered best practice?
It will make no measurable difference to the performance of your code.
In terms of best practice, I believe the general advice is to prefer signed integers. However, if you’re doing arithmetic which might overflow, this is only well-defined for unsigned ints. Overflowing a signed int is undefined behaviour.
So, my advice would be: use signed ints, and ensure your values never overflow.