Yes the UFs certainly take the bite out of the Atomas also. I had a 4oo with a tiny high spot & just used the corner of a UF to knock it down. Problem solved in seconds.
The best way to lap UF's that I found was with a slurry of SiC powders starting@ 80 grit or lower on float glass. Very fast & saves the diamond plates. Diamond powder slurries would work too but more exe.