Originally Posted by Andrew R Stewart

Rear der max cog capacity is also controlled by the der hanger length. Back in the day when horizontal slots were the standard one could change this dimension by moving the wheel forward or back in the slots to get the guide pulley to cleat the cog underside. With today's many vertical dropouts this is no longer possible (although I have seen slight hanger length differences between OEM and aftermarket hangers that fit the same bike).

I also like the rear der cage designs that place the guide pulley off center from the cage pivot. This allows the guide pulley to raise or fall WRT the cogs as the cage plays out or takes up chain slack. The bigger the cog the more the pulley drops giving room for that cog. The 591 ders (and most all previous Shimano ones for decades) have this design. With the guide pulley and the cage pivot on the same axis the chain length no longer influences the pulley/cog gap.

So my suggestion is to not use the 592 version. Andy