I ordered about 10 quads from E.L.F. ($1 each) and if they ever get here, I am going to put all of my non-Mac colors in there like my NYX singles and trios, Milani, and Jane colors.

Like SoSoAmazin, I would take the plastic part out out of the quad and place the NYX singles in instead.

This also works if you take out the plastic part of a Mac 15-pan palette and put the NYX shadows in there.

HTH!