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We have found this to be an essential FIX to the Ender-3 and not an upgrade! However, as others here have noted use of another 4mm nut to capture the bolt to the bed will in turn require a change to the spring to one with a larger inner diameter so that the spring goes over the nut. You may also need a shorter spring. The heavier/stronger the spring the better. A further complication to the Ender 3 is the inability to adjust the Z limit switch without modifying it. So one needs to find the optimal sizes for the spring or it will not fit... or mod the limit switch mount.
An update... After locking the m4 bolts to the HBP and attempting to replace the bed on to the Y axis shelf we learned that the holes do not line up. One was off by about .5mm. It had to be drilled out to a looser tolerance. Prior to this FIX the bolt must have been off perpendicular. As such it would have made leveling the bed a bit trickier. If this is systemic it's not good for Creality.