Agree on the whole that summing is summing is summing. Most DAWs
these days will use floating point (either 32bit or double
precision) and A+B=C no matter what.
In Integer math. In floating point math, A + B = C +/- (very small
rounding error).
At one time the USA's NASA (National Aeronautics and Space
Administration) used Integer math to track their satellites.
I don't know if NASA is still using Integer math or has gone to
Floating Point math for the calculations now.