The Neen is the flattest one as far as I know, flatter than the DLX (Ishod/Worrest) and Crob at least.
Speaking of Paul Schmitt, he just did a twin board for Dylan Jaeb (no idea if it's for a yet unannounced future board sponsor or just getting himself a bunch of blanks).
8.25 x 31.75, 13.75” WB, 6.875” nose/tail, that's quite short!