Matan1: The list is almost only of MO rabbis. And it isn’t as widely used even in the MO community as supporters tout. (Check around with recent MO couples and you’ll likely find most never signed.)
Outside of the MO world it is virtually unheard of. I saw a YT video of Jeremy Stern claiming Rav Shmuel Kaminetzky told him he supports it when he bumped into him on a plane ride. I called Rav Shmuel and he told me he certainly does not recommend or encourage it but rather if the other side asks for it he doesn’t think you should fight them over it since he doesn’t have a halachic objection to signing it. (Rav Elyashev does halachicly object, as his teshuva states.) Rav Shmuel specifically told me it should not be recommended or encouraged.