Yes, gruntiness has advantages in terms of pushing the low end a tad down - IF it is sufficiently fast to give you peak power spike you can also push the marginal limit down, otherwise not really.
I can not see any connection to gruntiness and whether a kite hindenburgs or not ?
It is all in the design and hugely the weight distribution of the particular kite - so you have many non grunty LEI light kites that does NOT hindenburg, thats for sure
Weight is also extremely important - but again, a balance between hydrofoil low end abilities and durability needed when used on TTs and in the surf.
A grunty kite is good in foiling when you are learning, or if really heavy they are in general preferred for "everything", as opposed to lighter riders who usually seek huge depower kites instead.
But many do not like the grunty ones for hydrofoiling because they will "run away with you" when you got an efficent hydrofoil, especially when going toeside where you dont want this
So some like kites with a more smoothed pull, meaning less grunt but a lot more depower and faster - AND the ability to create good apparent wind power (meaning not too low AR) so you can loop the kite to get going, but still good depower WHEN you are riding.
Both "extreme" ends of this, are often not that liked, at least individual taste.
Find it interesting, as I know, talked to a LF responsible last summer where we all rode foils 10 days together using many different brands, that they got aware of above issues for hydrofoiling - so one might think they have adressed it and changed some of the design parameters in order to fit most likings