Well .... Start over.
A Leader is a completely different thing from a Line, mostly because it can be linked to the annotation or block or whatever was placed in association with it. That's why its end follows, and maintains its original positional relationship, when you move the Block [that's exactly what it's supposed to do]. But if you expect it to know when its line element(s) is/are crossing the Block if you move that a particular direction or distance, and somehow change to connect to the other side [or the top or bottom, perhaps?] of the Block, I think you may be out of luck. Maybe a before-and-after image would shed more light -- it's possible that it could be done through some very sophisticated reactor that would look at the bounding box of the Block relative to the various points on the Leader, but it would certainly have a whole passel of possibilities to take into account.
In what way does Stretching not work? Is it merely that it does the same thing that moving the Block does?
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Kent Cooper
Kent Cooper, AIA