Changing the size of a proportionally constrained line element can yield some interesting numbers… but it doesn’t seem like it should do that. In the example, the width never changes, but the height changes exponentially. Perhaps that’s the intended effect, as it is just supposed to be a straight line, but sometimes the number increases when the size is being decreased.
Good catch; filed and will investigate a fix. Thanks!
(The workaround is to enter the vector shape and change the position of an anchor point)