Select Mirror needs a tolerance setting

How is the Select Mirror feature not having a tolerance setting. I have a mesh that is pretty much symmetric, there might be some differences in the later decimals of the positions but it is still not selecting them. A feature like this definitely needs a tolerance setting in my opinion. For me it is pretty much all of the time useless when you import a very very symmetric model from zbrush but it has some really negligible deviations.

Thanks!