Leniency for sefer Torah that survived the Holocaust

I once heard that there are poskim which lechatchillah allow leniencies in  a sefer torah saved from the Holocaust. I've even heard that a Holocaust sefer can be used lechatchillah even if the majority of opinions render it problematic, so long as there is a "yesh lismoch",  it is OK to use. For all other sifrei Torah such a rule would only apply if you have already taken it out and found a problem during the laining (we can be lenient because of tirchei ditzibura).

Has anyone else heard such a thing and if so, can they please advise which poskim hold this and are there any printed teshuvos on the matter?

Thanks