I rechecked everything and set the slack with the suspension set so the sprocket, swingarm pivot, and rear axle lined up by removing the seat and using a ratchet strap to hold the position. After torquing the axle the lined up trio ghastly 18 mm of slack with about 2-3 lbs of up and down pressure. With the suspension fully extended and on the center stand, the chain is just taut when contacting the lower chain guide and the slack measures 30mm when pressed down. Given these results I think if on the centerstand and the tight chain just contacts the lower guide and the upper run of chain is taut, it is correctly tensioned. Again my bike is a 2019 F750GS with the dynamic rear suspension.