 Nearly closed semicircular slit

With $m(z)=(z+1)/(1-z)$, the compact H-hull $K_L=m^{-1}(i(0,L])$ is a unit semicircular arc attached at $-1$, with a narrow passage near $1$. As $L\to \infty$, its normalized mapping-out function of a compact H-hull tends to $2$ at each fixed point of the interior bay. Points in that bay tending to $-1$ therefore have displacement approaching three. The order of these two limits is important.