Flipjack - Any experience with them?

I added an additonal 1/2" temporary spacer at the top where the 1/8" 2" spacer goes and now it works perfectly, tucks away real nice. I don't know if I actually need 1/2" that is just the material I had. Now I have to get some additional 1/8" x 2" spacers (washer) I am sure they are not going to be easy to find..