One difference is that it is an open question whether these properties are equivalent level-by-level in the supercompactness hierarchy.
Specifically, on the one hand, if $\kappa$ is $\theta$-supercompact, then one gets the ineffability property for all $A\subset P_\kappa\theta$, at the same level of supercompactness. That is, if $\kappa$ is $\theta$-supercompact, witnessed by embedding $j:V\to M$. If $\vec A=\langle A_\sigma\mid \sigma\in A\rangle$, where $A_\sigma\subset \sigma$, then consider $j(\vec A)(j''\theta)$, which is $j''B$ for some $B\subset \theta$. Almost every $\sigma$ has $A_\sigma=B\cap\sigma$, since $j''B=j(\vec A)(j''\theta)=j(B)\cap j''\theta$, and I think that this is the threading property you have in mind.
But meanwhile, on the other hand, although every supercompact cardinal $\kappa$ has a Laver function for $\theta$-supercompactness, Laver's argument is not level-by-level. Specifically, his argument shows only that every $2^{\theta^{\lt\kappa}}$-supercompact cardinal $\kappa$ has a Laver function for $\theta$-supercompactness. One needs a higher level of supercompactness initially than one gets for the Laver function.
In my paper A class of strong diamond principles I call attention to the following open question (question 5):
Question. If $\kappa$ is $\theta$-supercompact, must it have a $\theta$-supercompactness Laver function?
This question is, of course, connected with the number-of-measures problem, since if there is a Laver function for $\theta$-supercompactness, then of course there must be at least $2^\theta$ many such distinct normal fine measures on $P_\kappa\theta$, at least one for guessing each element of $H_{\theta^+}$. It is not known whether than can be exactly one, except in the case $\theta=\kappa$, which reduces to measurability.
Meanwhile, the existence of a $\theta$-supercompactness Laver function, although not yet known to follow from the $\theta$-supercompactness of $\kappa$, does not require any extra consistency strength, since as I show in the paper, if $\kappa$ is $\theta$-supercompact, then fast function forcing with $\kappa$ will add a generic Laver function for $\theta$-supercompactness.