The Meucci 'Black Dot' was introduced as a low deflection shaft, though it doesn't fare very well when compared to the other shafts in that category.
Ivorine4, which I guess is what the OP is referring to as Ivorine3 is no longer available, is about the hardest, heaviest ferrule mtrl. made.
It throws sparks when cut, even with carbide tooling.
What low deflection characteristics the shaft had to begin with, will be severely compromised by the addition of such a heavy ferrule.
As Dave mentioned, shorter would be better, but be mindful that whatever you reduce the ferrule length by, you will also be reducing the overall shaft length by an equal amount. 1/4~1/2" may not be such a big deal.
Then there's the consideration of 'tenon leverage' which I won't go into here as I've written about it several times now. Please feel free to do a search.
It's one thing to be critical of a particular application/suggestion, it's quite another to offer a better solution; so here it is.
We are fortunate enough to have in our midst, a very enterprising CM by the name of John Rocker. John has developed a very light-wght. ferrule comprised entirely of wood. These are similar in nature/design to the ferrules found on the OB shafts. The use of that ferrule alone will aid significantly in reducing deflection, thereby making the Meucci Black Dot a much improved shaft.
Personally, I'd still reduce the length of the tenon/ferrule because of tenon leverage. Reason, an even better playing shaft.
If the concept of a wooden ferrule is just too new (or whatever) for you, then I would suggest a thin-wall LBM 'through' ferrule. There are even lighter plastic ferrule mtrls. but they may, in this case, take away from the hit.