I cut down metal darkslides for mine. With horizontal 5.5x14 I have to always compose the image for the upper half of the GG. The modified darkslide is heavy enough to slip a little if I try to use it with the image on the bottom half of the GG. I need to have the full 14" of the modified darkslide along the bottom of the film holder for it to be stable.
With 8x10, there usually is no problem, but one has to make sure the modified darkslide is straight in the holder before exposing. Using an 11x14 for 5.5x14s shares one of the advantages of the Ritter 7x17. The ease of doing verticals.
Ritter 7x17 on x-ray film, carbon work-print. (lens probably a 19" RD Artar) A little bit of glare on the print in the reproduction. My Boys, Prairie Creek Redwoods State Park