As a rifle shooter I found out that it doesn’t make much difference where your rifle sights are set or whether the rifle shoots the bullet where the sights are pointed. The only thing that darned thing has to do is to shoot the same way next time as it did last time.
We can compensate for bad shooting. We can compensate for dodgy sights. But we cannot compensate for inconsistent performance. Much the same thing in photography.
If my camera shoots with a white balance that is too low or high, I can raise or lower the result in the finished product to a very great extent. The RAW file gives me a chance to do this. If I am using a program that lets me do batch processing, I need only correct one image and let the machine do the rest. Of course, it is nice to have a JPEG image spot-on, but mistakes in estimation or metering do occur.
Likewise if the aperture or shutter speed is slightly off it is nuisance – but no more so than the white balance. A RAW correction puts it right again quickly.
Where the real misery starts is when the mechanism is out of adjustment and gives inconsistent errors. These can be corrected but need to be done one small bit at a time. And time is what it will take. And time taken will eat up money.
You might also make the error of constantly changing your mind and trying to ” re-tune ” the exposure or focus as you go with a series of shots. You’ll then have to micro-adjust every frame as you process them, thereby shooting yourself in the hip pocket.
Moral? Make a decision as carefully as you can, but once made, stick to it. Check your LCD screen from time to time for re-assurance, but do not fly to the controls to tweak every shot. You’ll regret it.