How to make dual illuminant profile in DNG profile editor?

Question

I have just started working with the DNG Profile Editor.  In another discussion I commented on the clarity of the instructions provided by the tutorial.  I had no difficulty creating a single illuminant profile using the X-Rite color checker passport.  But when it came to producing a dual illuminant profile, following the instructions exactly, I was stymied. 
1.  Open dng image of Color Checker photographed in 6500K illumination.
2.  Open dng image of Color Checker photographed in 2850K illumination.
3.  Select Chart tab in editor.
At this point one is instructed to "Click the 6500 K-lit ColorChecker image window to select it."
But the 2850K lit image (last loaded) has replaced the 6500K image window (at step 2) and I can find no way to reopen the 6500 K lit image window in order to proceed to the next step.
As a matter of interest, why do these instructions suggest setting the pop-up window in the Chart Pane to "6500K only" and then create color table with first image.  Thereafter select second image, set pop-up window to "2850K only" and create color table.  I seems to me that, having loaded two images (even if I can only see the second image loaded) one should choose "both color tables" and then create color table.  In fact I have tried this and it does produce a profile, but I have no way of determining if it is a correct dual illuminant profile.
Please help.

Answer 1

2. HYPERLINK "/people/MadManChan2000"MadManChan2000,
Oct 21, 2013 9:09 AM in reply to blumesan
Note that the "Both color tables" option always creates a single-illuminant profile. The "Both color tables" option means that the computed color corrections will be applied to both color tables (i.e., the color table for the first calibration illuminant, which is usually Standard Light A, and also the color table for the second calibration illuminant, which is usually D65).
After playing around with the Profile Editor for a while, and examining the results with dcpTool, I now understand (I hope) what Eric is saying. In his language a single-illuminant profile is one created from a single dng image using the "both color tables" option (without regard to the illuminant used to capture that image.) When one does this (using Adobe Standard as the base profile) an examination of the resulting profile with dcpTool shows the following:
Two illluminants are identified: 17 (Std A) and 21 (D65).
Color Matrix 1 & 2; Forward Matrix 1 & 2; Hue Sat Delta Tables 1 & 2.
Which certainly gives the impression of a dual illuminant profile to novices like myself.  My guess is that the PE software itself applies a default assumption of these two illuminants, corrects the image for each illuminant and constructs two color tables, one for each illluminant. When used, the profile will interpolate between the two tables based on the white balance of the image being edited.
If this is indeed correct it makes me wonder in what way does such a profile differ from a dual illuminant profile created from two dng images, each captured under a different illuminant (2800K & 6500K) as described in Tutorial #6 of the PE instructions. These instructions contain the following description of such a dual illuminant profile: "The result is a single profile that performs well under a wide range of illuminants instead of a single fixed illuminant."   Which really make me scratch my head. Should one conclude from this that a single illuminant profile (created using the "both color tables" option) will perform less well under a range of illuminants?  Will it perform well only under a narrow range of illuminants centered around the illuminant used to capture the single image? 
As a footnote, it is worth remarking that I (and perhaps others) have been confused by examining profiles created by the XRite software when using only a single dng image. Examining such a profile with dcpTool one sees the following structure:
One illuminant only #23 (D50)
A single Color Matrix table.
A single Hue Sat Delta Table.
Thus one comes to expect this structure in a single illuminant profile.
I would be very happy to see Eric's comments..