Haha, the up side is I dont think there is a wrong way to do it.
The strong reason you posted is why I would mount the shock tilted towards the equalizer. As the spring gets longer as it moves up the axle will move towards the equalizer compressing the shock more. Will also slow down rebound as the axle moves down and more towards the solid mount.
I envision the shock tilted away from equalizer not moving much while the axle is traveling up and away from its upper mount.
I guess thats good if you warranty the shocks you sell :B
I say that jokingly because I really dont know which way is best, but thinking about how things are moving I would go top towards equalizer.
Damn good question though !