The first palaeographers to assert the Ms is in a humanist script?

[Beatrice]

There was extensive correspondence in the original mailing list about this topic, as the result of a report from Sergio Toresella, who may not be a palaeographer, but certainly has a vast knowledge of medieval herbals.
He spent some time with the original MS in or just before December 1995:

"The VMS is, with certainty, authentic; not a fake.  It was manufactured
in the period 1450-1460.  It was in France for a while: the month names
on the zodiac diagrams are in French in a French handwriting.  The book
itself comes from Italy; the mysterious writing is done in a round
humanistic style found only in Italy in the second half of the 1400's.
There are similarities between the organization of the VMS (including
the balneological section!) and that of other Italian herbals of the 1400s."

(There was quite a bit more).

In summary: the date of 1450-1460 follows from his identification of a humanistic style.

Do you know how Toresella could explain the angular and thick strokes of some graphs? The roundness of "o" or "a", for instance,  is irregular throughout the ms. That is, it is not a continuous feature. 
The script seems to me that of a craftman or someone who was used to writing lively and quickly.