Before you say just uncheck "Generate Support", here is the issue (for example)...
I have two models I want to print at the same time. I need supports on one, but none on the other. I figured I'd just go into "customize Supports" and remove the supports from the model I don't want them on. The problem is, if I do that, hit ok, then slice, the supports generate anyway. I can customize and they stick, except if I remove all the structures from a model, in which case they are created anyway. I can generate then remove all but one column, then the edit sticks, but as soon as I remove that last one, they all come back (for that model).
Not sure if it's a bug or by design, but I see the need to be able to remove all supports from a model while leaving supports for others in the same pass. If not a bug, then consider it a request.