The most important rule of audio recording is "always be ready to roll tape". What the engineer does is of little consequence compared to the talent. Don't ever fuck up a keeper take.

Recording with some extra bits means that even if your gain staging was bad, you just get some extra uncorrelated noise, not correlated quantization distortion.

As for whether this stuff is perceptible, there are two issues at play. First, differences which are not perceptible during production can result in a perceptible difference in the final product. This is easiest to understand with a visual analogy: if you have inadequate resolution of an image during processing, the end result may be slightly defocused and smeared.

Second, as I described elsethread, quantization distortion is a particularly pernicious form of degradation, poisonous in small amounts. https://www.youtube.com/watch?v=8KkS4NSv-0M It is hard to listen for it during production, so we defend against it by giving ourselves lots and lots of headroom.