If what I understand you are saying is true, that is the stupidest thing I've heard.  If the Memo is for the "transaction as a whole", then it should display on any report that includes the "transaction as a whole"...otherwise what is the point of filling it in?  I have added in the American Express accounts and rerun, and the report looks the same.

Only if I run a report using ONLY the Amex does the memo/description appear, and then it is not filtered for the distribution account.  If I try to even just group that report by account, the memo doesn't appear again, except under the AMEX account, so there is no way to see just the distribution account transactions with the memo, making the detail transaction report pretty useless (can't use it to validate an expense account for example).

Not your fault, but a really stupid functionality, as it isn't possible to get all the detail entered by expense account, which is a very common need.  As (in my case) the transactions are added from the credit card transactions to reduce data entry, there is no way to populate the description field (especially when the prefilled memo field is perfectly sufficient), without manually entering the entire transaction and then matching them.  That is a huge waste of time.