To get the kind of reticulated shrinking tail that you want, you'll probably need to do something like extract edges from that version you had from sweeping, then use those in a loft with the "Loft style = straight" option to build a ruled surface.

That kind of loft has a similar look as a mitered corner sweep, but there are differences - a mitered corner sweep produces the corners by an extension of the main section of the sweep, so it keeps an even thickness in all areas.

When doing a loft with "Loft style = straight" between angled profiles, it produces sections of different widths like this:





That's the kind of thing that happens if you try to more directly connect angled miter profiles (even though in this example the 3 profiles are the same size, just rotated at different angles).


That variation can be reduced in size if you have more numerous sections that don't deviate by too much of an angle from one to the other though. But I hope that shows the difference from sweep.

- Michael