The whole oil rancid stuff is referring to non sterile oil on a shelf without alcohol or preservatives. Once in sterile solution with bb/ba and sealed...those numbers are out the window. I've seen people use 10 year old gear no issues and I've heard of well beyond that for guys finishing up their old parabolan stash. Never once have I seen or heard sterile, preserved and properly stored gear going rancid. The real question is best storage and how does powder or solution differ (if material or if at all) in decay rate of active compound. Never really seen a knowledagble conclusion based on data set but given above and reports I'd assume it's a non issue in any case.
One thought, for test E in particular I've heard multiple cases of initial batch being fine and a year or so later a new batch from same stored raws had a ton of pip (same recipe, same raws etc). Maybe something about test E.