One often repeated argument against the acceptance of Murex techailes is that "the Gedolim" don't accept it. Certainly there are many Gedolim who considered the issue, at least superficially, and did not start using the Murex. Often one Gadol would rely on another, for example Rav Chaim Kannievski (as can be seen in his responses in Dass Note, "כל רבותי לא החזיקו מזה"). My question is, who are these Gedolim who do not to accept this for their own reasons, without falling back on the opinions of others, that lesser rabbonim then supported themselves upon?

Note that it isn't always obvious who is really relying on others. Most responses from Rav Chaim would indicate, from lack of evidence to the contrary, that this was his independent conclusion. It is only from his more detailed response that we see not like that. But as far as we know, whose rejection is his own?