I would like to move the columns shown here further to the left, and others, further to the right. How can I edit?
I do not think the location sublist can be edited. I believe it is fairly common practice for people to make their “own” custom sublist which you have control over and display that by default instead.
May you advise where to “Start” on this? I could create my own Location Sublist to mimic?
Have you made any custom sublists before? You can create a saved search with the information you want. When you create the search, there is a checkbox at the top that says Available as List View. Once your search is created, go to Customization -> Forms -> Sublists and create the new sublist that is based off your search. Then modify the form that you use for your item records and add your newly created sublist to it.
Available as List View