But honestly how many shops are willing to admit their lenses PD or axis is off? Most if not all of them will just try to cover up if they can becos frankly hey know that customers have no way of testing the accuracies of lenses except seeking advices from other shops. They will give excuses or just tell you to GET USED to them. Ofcos its sad, even hearbreaking at times. But most opticuans dont really care. Sad truths.
I don't know about the cover-up part, oldbreadstinks may be able to shed more light on that. In any case, I think a good shop would check in the first place before dispensing the spectacles, thus realising the mistake and being able to correct it before giving it to the potential wearer.
The testing-of-accuracy is usually unnecessary though, and can lead to a psychological bias which makes the wearer unhappy instead. If it's clear and comfortable, leave it. I have seen cases where the patient cited discomfort, then was resolved without any power or PD changes by simply giving it back to them a few days later - they probably had the impression that their eyes were sensitive and so they will never be able to wear a spectacles without the power being adjusted at least once.
In addition, every refractionist has their own way of adjusting the final power, which depends on various factors like the angle of the lens, distance between the lens and the eye, what visual tasks you perform with the spectacles on, what is your previous power, how sensitive you are to power changes, and so on.
Like I've mentioned in an earlier post, your real eye power could be -1.86, the final prescription -1.75, and the actual lens power -1.81.
Or, your real PD is 62mm but due to frame curvature the PD is set to be 63mm, and the actual PD 64mm due to deviation (within acceptable range still). In most cases the prismatic effect induced isn't likely to cause any major issues, i.e. most people are not likely to feel any discomfort.
So, instead of bothering about numbers, find a practitioner or shop that you trust, and accept them with lots of wholesome love.
If nothing local satisfies you, then you can ask me for recommendations over in the other side of the globe.