I thought the same thing, But when I tried it it seemed that the spacer didn't interfere but wasn't sure. I went and bought some plasterseen like silly putty
and stuck it onto the end of one axel and bolted both axles in and when I pulled the axels out I had almost an 1/8 of an inch of room.
I'm not what case I tried it on but do that same test and see how thick the palsterseen is after bolting in the axles, but I bet your safe to leave it in.
I also had Yukon axles with the green bearings. I'm not sure if there is a slight difference between the 2 different types of green bearings but either way the axle should sit extremly close to the same spot in the case.
