Vayigash: The Trup On Rav

A quick correction by Shadal about the trup on the first pasuk in Chamishi, apparently based on theory of trup rather than any particular manuscript evidence. (My assumption here is based on how elsewhere, he cites manuscript evidence, as well as how once he parses it he then proposes the trup in line with this parse.) He writes:

רב כוחי עוד יוסף בני חי : אחרי ראותו העגלות אמר די במה שהייתי עד היום ביגון ואבל כי עתה אין עוד ספק, כי יוסף בני חי, ומילת רב ראויה לזקף גדול.

That is, he would change the tevir under rav to a zakef gadol. This makes sense because while tevir breaks up a clause ending in tipcha, the zakef breaks up a clause ending in etnachta. Thus, as written in Mikraot Gedolot, it would read:
וַיֹּאמֶר יִשְׂרָאֵל רַב עוֹד-יוֹסֵף בְּנִי חָי
turning into
וַיֹּאמֶר יִשְׂרָאֵל
רַב עוֹד-יוֹסֵף בְּנִי חָי
which in turn gets broken up as
רַב עוֹד-יוֹסֵף בְּנִי
חָי
which in turn gets broken up into
רַב
עוֹד-יוֹסֵף בְּנִי

This is weird because rav should be broken off before chai -- otherwise, it suggests that it is part of the phrase.

In contrast, with Shadal's corrected trup, we have:
וַיֹּאמֶר יִשְׂרָאֵל רַב עוֹד-יוֹסֵף בְּנִי חָי
becoming
וַיֹּאמֶר יִשְׂרָאֵל
רַב עוֹד-יוֹסֵף בְּנִי חָי
and then within the quotation, we have
רַב
עוֹד-יוֹסֵף בְּנִי חָי

Which is what Shadal says it means -- it is enough {my days of mourning} -- my son Yosef lives.

Now, is there any other way of parsing this pasuk such that it can work with the trup? I don't see any, nor have I seen any commentator do this, but I have quite possibly not looked far enough.

Update: That is not to say that there are no variants in accordance with Shadal, just that my strong guess is that he is basing himself on the logic of trup. Thus, using some chumashim from JNUL,
1) in this one from 1490, it appears to me to be a mercha kefulah, which many consider a reduced tevir.
2) In this one from 1491, in Naple, we actually do have a zakef gadol. This is the only one of those I checked which have it.
3) In this one from 1494, it appears to have just a meteg on it. But that makes no sense. And at the same time, some have tendency to make their tevirs very vertical, so maybe that is what we are seeing
4) In this one from 1518, we have a tevir, and it is written quite vertically.
5) In this one from 1521, this one from 1524, and this one from 1525, we have tevir.

Meanwhile, in a chumash with Minchat Shai, I see no correction of the tevir to a zakef gadol.