"We have a vague shmua", as if you're the judge and jury?
Also, have you asked Rav Yaakov's talmidim? That's how mesorah in psak works. No one is mechuyav to fill you in
Yes, people on this forum have reported/linked to nothing more than vague shmuas. - Have you asked R Yakovs talmidim? If yes feel free to post that!
Im not a judge or anything. Its just that R Moshe actually addresses this "rumor" - that this is the minhag in Lita, and says that it is not true. IMHO it is reasonable to assume that the vague shmuah that I have heard, and which is mentioned in R Shachters publication, is indeed the same one that R Moshe is dismissing as a mistake.
Unless you can please point me to a more reliable source.
Besides that the actually sevorah of this heter is also pretty vague to me and takes some "pretzeling" to explain. - Also just mho.
So to summarize, I dont know whether it is true or not; but for now all I know is that R moshe says that it is unreliable.