DY
“At this point, it’s considered more of a minhag than a chumra, but based on a time when there was a possibility, which meikar hadin we don’t need to be concerned about, which nevertheless some were machmir on”
Very well said!
Thus the notion that there is an actual “chasash chometz” with gebrokts today is silly both because of the metzius and becasue of the inconsitency in how we treat this chasash chometz (though I dont blame you for not being willing to outright say that)
“Now, some have the minhag to be machmir even though we grind the wheat better and have thinner matzah, and they keep the minhag as their ancestors kept it when there was a (remote and not halachically binding but real) possility of chometz.”
yep. I have this minhag!
Yehudonya
“Could somebody explain why it’s OK to use keilim for gebrokts on the eighth day and then use them the next year on erev Pesach?”
i can! becasue that is the minhag!!! The very same minhag that assers gebrokts allows the kelim the following year!
” It’s not a full 12 months. Is it miktzas hachodesh k’kulo?”
Interestingly some only eat Gebrokts on acharon shel Pesach when the following year is a ibbur yahr so that there are (at least)12 full months until the next PEsach. Nitei Gavriel is a great source for minhagim in general particularly among various chasisdish groups (I dont have it in front of me, but If youd like Id be happy to provide details)