Mirror Distance Options

Create a new setting available for all symmetry/mirror settings that allows you to mirror (for example) edit mode vertices that aren't 1:1 symmetrical. So, if you had a mirror distance of 0.1 m let's say, then it would influence that vertex/vertices' exact mirror location + all within the mirror distance. If there are multiple vertices within 0.1 m of that vertices exact mirror location, then it would influence all of the vertices in that range.

The default option being a distance of 0, (or an extremely small value), whatever the current value is to calculate mirroring.