Both front and rear were revalved, so I have headroom to go stiffer on the springs.You have a good split, ride frequency wise, though my calculations do not take into account the CSS swivels. I'd just go up in rate to what ever the next rates you can get are.
Did you get the rear shocks revalved too?
Try 500/700 or 550/750.
CSS swivels add a degree of camber. Not sure if that’s because the hole for the strut is offset moving the swivel further outboard, or just the angle at which the hole to receive the strut is different. Not likely to impact the MR by much.
What MR are you using for the front?