I’m struggling to get to 580
L frame X: 457.6
Stem x: 85
TSP max x: 27
So the maximum pad mount x is 569.6
Minimum pad offset is 51.2
Which gets us 518.4 max pad x rear
Or 558.4 pad x centre
So Dave L is fine, Fishy - depends on the tolerance you work to
This is further complicated if you want tilt - the Angled Switch Plate gives a fixed 9deg - it is supposed to be used at the base of the pedestal so can have a significant impact on pad x when you tilt the whole tower.