Our two KF700's are both the 31" rip versions, neither with an overarm guard. With the riving knife mounted guard, nothing prevents you from cross cutting a sheet in half other than ours being short sliders with the fence usually on the operator end of the slider.
I don't know what the Felder overarm guard mount looks like. However, the overarm on my Panhans saw has a horizontal tube mounted to the back of the saw chassis. The arm is movable or removable with just one kip lever on that horizontal tube. It has 49" rip capacity, but the guard is movable far enough to probably accommodate 60" if you needed it. It's a super simple clever design.
Jason Holtz J. Holtz Furniture
3307 Snelling Ave. South
Minneapolis, MN 55406 612 432-2765
-- Jason J. Holtz Furniture 3307 Snelling Ave. South Minneapolis, MN 55406