Common saychel
It isn’t totally irrelevant, as his grandson was the compiler of the Igeros Moshe so his explanation of an ambiguos teshuva certainyl carries soem weight, and his son in law was the one with whom he discussed medical halacha.
Also I said “His sons (R Dovid can be seen on YouTube supporting this) and son in law…” I can’t help but notice that you left off “Sons” Was that deliberate? why?
Are you saying That R’ Dovid testifying what his father held is “completely irrelevant”?
As an aside, I have no problem with you saying R’ Dovid testifying what his father held has no bearing either(though it does sounds strange to me) and all that matters is written teshuva beseder so read the teshuva. Skip that line of mine . I think it matters, but if you don’t, I can live with that. BUT you can’t say talmid x said R” Moshe held qrs. Thats inconsistent
“do you quote R Aurbachs son in law opinion as his? ”
No not as his, but if his son said That R’ shlomo Zalamn held xyz, then of course I ‘d say his son held so. Particularly if R’ Shlomo Zalman Wrote several teshuvos that strongly sounded like xyz
how about Rav JB Soliviackis son in law. ”
Of course! all the time
“Do you quote Bar Ilan opinion as the Nitzivs opinion because he was his son?”
Again if he said his father said xyz then I think so. why not?