@sjaehn no, for shipping with a commercial product without worries.

typical CC-by license makes the music you produce using those works (samples, IR files, etc) also bound by the same CC license, which is terrible to give to users freely.

I am looking for stuff that is basically public domain, where I can remix, modify, rename, repackage, whatever.
Some good CC-0 sample libraries exist, but I am unable to find IR files licenses similarly.