Thank you again for the quick action and for the answers here. Very, very helpful.
As a FYI on this last Q, I found searching on "UHD" was more effective than "4k" as the latter returned a lot of HD results where they had "mastered in 4k" in description.
To the answers about using "**restoring purchases will get the unmapped version removed",**that won't work to address any issue with titles synced from MA because you didn't buy it form MSFT so you don't have the title in your msft purchases so there isn't anything to restore.
Regarding viewing your collection on 'purchased video', I was able to see where to export it within the Movies and TV settings section however it results in a web page full of unusable data. Seems as though it is CSV but I wasn't able to get it to work from a text file or directly within excel.
Not a huge deal (to me) but certainly a possible smaller barrier to getting heavier purchasers from using msft as default since you have to go to multiple places to get a full list of owned titles. Certainly bigger issues like the fact that the system doesn't currently let you buy a higher resolution version of a title you own and navigation/filters and transport controls for movies and TV are comparatively extremely lacking (can't filter on movie release year, mpaa ratings, genre, etc), but all the little barriers vs other providers make it less likely folks will default to MSFT's store.