One can potentially get away with all kinds of things in a contact print which would constitute annoying misdemeanors given a significant amount of enlargement. Going back to the last of the ancient posts, which returned to the original question of regular vs Quickload 4X5 holders, the Quickload/Readyload options never did hold the film reasonably flat, especially at the insertion side. I had to make my own special holder to solve the problem. And yes, the difference is readily apparent in side by side actual enlargements.

Likewise, things like vacuum and adhesive holders for 8X10 film have been developed for a good reason. Regular holders don't always hold the film flat. How much lack thereof can you get away with? A quarter inch is not a misdemeanor - more like a blatant felony. Why would you even want to sacrifice 2mm? That's just plain sloppy. Depth of field management with 8x10 cameras can be a complex question involving both logistical and esthetic factors. But what you intend to be in acute focus on the film plane, should be, without compromise.