Vochindik: Techeiles is not a Chumro.
Tcheiles is what the Ribono Shel Olam specifically asks us to wear. You even say so twice a day.
Reb Chaim Kanievsky – who knows very well what Rav Elyashiv said – told a big Askan from Monsey last Pesach that if someone looks into the matter thoroughly and is convinced that this is really Techeiles then it is not a question of whether or not he should wear it, but he MUST wear Techeiles.
“Ehr Muz Dos Onton”
Reb Chaim himself never studied this topic in depth so he doesn’t wear it.
This conversation with RTeb Chaim is recorded on video and I, myself, saw the video last week Sunday morning at the shul of TriStar in Woodbourne.