The other point to consider is that EL, when taking vendors to court, tend to mention how the vials are in increments of EL's doses (they always have some way to get the "even" amounts to work in their favor) - "even" meaning 10, 15, 20, 30 etc... - So some very astute vendors will get the average of the vials tested in that batch and use that average on their labels be it 28.4, 31.1, 11.6, etc.... so that abates one argument from EL.
Personally, I use the averages to determine how to reconstitute the vial and get the particular dose accurate for those items, such as GLP1's where I want a very accurate dose.
Other peps that I'm not so concerned about accuracy of the dose, I'll not worry about it nearly as much.