I say yes, absolutely. Less variance from shot to shot should translate to less variance on the target. However, I'm not sure how one would quantify net effect of perfectly uniform velocity. As reloaders, we control the things we can, like measuring powder the same way every time, keeping brass in batches and trimming/sizing them the same way, we use the same brand components. Unfortunately, there are a lot of things we cant control, like the consistency of powder and primers from lot to lot, the construction of the bullets, etc. Fortunately, we have a lot of quality components available to us. However, at the end of the day, we do the best we can with what we have.

I'm like you - when I test loads, I'm not going to distinguish between a 1.4" and a 1.6" group. On the other hand, you can really see the difference between that 1.4" group and an 1/2" group.

Looking at the variance in velocity might be a handy bit of information, but it needs to be correlated to other data, like group size, in order to be useful. If you're able to find a relationship between one and the other, you might be on to something. Just keep in mind that you'll need several data points to establish such a relationship. Its hard to say how valuable that information is going to be in the long run, but its interesting stuff nonetheless. Not to mention, if you do start to see some big fluctuations in velocity, it may help you diagnose a problem with components or procedure.