As already mentioned, DD-23 is not some official developer formulated by Kodak, so a lot less testing and expertise went into it. If you can't even get accurate dev time numbers from these instructions, how would you expect numbers for reuse?
Looking at DD-23, it is basically D-23 (or variants thereof) and a second alkaline bath to raise its shadow density and boost sharpness (i.e. try to make up for D-23's biggest deficiencies). If you use diluted D-23 as bath A, you will see less effect from bath B.