Person A will not see anybody beyond the even horizon, even in metre ahead. That is because one meter in a flat coordinates (which I suppose you mean) corresponds to infinite distance in the co-moving coordinates of the observer A.
Observer A will be able to see large objects (larger than 1 meter) ahead of him which still outside the even horizon. At the same time, ofserver at infinity will see observer A shortened in radial direction and becoming like a flat disk on the surface of black hole.
The crossing the horizon for observer A (if happened) would look not like crossing a spatial surface, but like crossing a moment of time: now he is before horizon, and now he is inside. All objects around him, ahead and beyond cross the horizon nearly simultaniously (with difference only of the time it takes for light to travel between them).
Something in meter ahead him in flat coordinates corresponds to a thing that crossed the horizon infinite time before he did, so he would not be able to see the observer B. Even if observer B is also outside the horizon, the distance between them would be so large that they hardly could see each other.
If you meant that the observers were 1 meter of each other in co-moving coordinates, then they both either outside the horizon or inside it. They cannot see each other in a meter but be separated by a horizon, because the horizon is null surface, it is not spatial surface.
Two friends travelling in one spaceship will cross the horizon nearly simultaniously, even if spatially separated (for a distant observer the length of their spaceship will become zero at the horizon).