I hear that.  It strikes me as strange how they built two separate screens for the Plot Builder for each - the implicitplot you mention is obviously a much simpler one.  I can't see why they built the two separate rather than together, and disabled a few options on the implicitplot one, but... I guess it's just "by design," as they say.

I figured out what it is.  You get quite different menus if you put in something like, say,

y= (x^2)/9

than just putting in

(x^2)/9

and opening up plot builder for the two.

If you include the y=, your menu doesn't include the "Find Discontinuities" option, among other things.  It looks like it was done with obvious intent, but the intent is lost on me.

So, I guess this case is more or less solved.  Thanks for the effort gentlemen.

I right click, go to Plots, opened the Plot Builder, clicked Options (I'm certain there's only one of these buttons), and the right side of the resulting box has the following areas:  Axes, Title, Captain and Miscellaneous.  There's only two check boxes on the entire screen, 'Filled Regions' under Miscellaneous and 'Constrained Scaling' under View.  Clicking the Advanced Settings under View or Custom under Color doesn't bring up any screen with this option, nor do any of the six buttons along the bottom (Preview/Plot/Command/Back/Reset/Cancel).  It's not in any drop-down menu. - obviously, it seems like it's taking me to a slightly different Plot Builder than everyone else.  I've went through every possible menu more than a dozen times.

Maybe I've got something wrong in my expression that modifies my Plot Builder to not give me the option?

... I can't seem to get the expressions I've used to paste here; another confusing problem, since I did it once before...