Given the influx of low minors talent the Cubs brought in over the past year, I could see them willing to sign a QO free agent. As you said, I could also see them reserving it for a top level talent (Correa, Seager, Semien, or maybe Rodon if you trust his health ((and I think they showed interest last offseason)). I think there's virtually no chance they sign Story, Taylor, Conforto, etc for this reason. There is still some good talent out there without that QO attached like all of the recent former Cubs and Stroman and Gausman. Though of course every other team will be thinking that too.