yeah EDL loaders for a bunch of production devices exist here [0] also more on various XDA Forum posts for stuff like unbricking guides. It is worth noting for people who don't
But reading QFUSES specifically requires an EL3 loader "edl qfp qfp.bin -> To dump qfprom fuses (only on EL3 loaders)" and I don't believe most devices programmers (especially as relatively new as the OnePlus 6) run under that privilege level.