Hummm, I got nothing, then, since according to the docs it "should" work. Sounds like maybe Workbench is filtering out those modes that are flagged "Requires ECS"? Wonder if there's a way to trick it, either by editing the display driver or through some time of SetPatch modification? You could always try messaging Jens, I believe he's active on EAB or some of the other Amiga boards.
Maybe try HighGfx or SuperPlus and see if those work? Just out of curiosity.
As another solution keep your eye on ebay, Super Denise chips show up pretty regularly for only about $20. Good luck!
