Not sure what "bottom out the floats" means, but if you lower the level slightly, you shouldn't need to remove fuel. I guess if your fuel level is waaay to high and you lower it to the bottom, it may put strain on the float's arm since the float would then be submerged in fuel. Shouldn't be an issue with minor adjustments though.
I'll defer to the 'experts,' but I've always run the level even (or close to even) with the bottom of the window. Keep in mind that float level adjustments may change AFR slightly.
