I understand you state "These will eventually migrate into an officially maintained terminology (likely HL7's UTG code systems)." I see no issue in doing this for the ballot. But, you must place these in a published and maintained code system prior to allowing implementers use of the codes and certainly before the CDex guide is published.

Many, but not all, of the codes could be added to the ActReason code system. Others would need to be someplace else. Plus someone must confirm these codes to not overlap in meaning with other codes. Finally, the description (the string display) for many of these needs to be improved for some because the meaning is not clear and can be misunderstood outside of the very specific uses you have currently envisioned for information request. You can provide shortened synonyms when defining the concepts so that displays can be briefer.

Please work with vocabulary WG to complete this work.