A very simple improvement that makes working with tables easier and helps people understand why a selection was taking forever is to put back the visual clue that a field is indexed.
In ArcMap if a field has an index then when you are viewing the attribute table you will see a tiny * next to the field name, this is really useful!
In ArPro you have to move the cursor over the field header and then read the tool tip that pops up to find out if the field has an index. This is slow and does not help you when you are looking at the table as a whole. Not even the fields design view indicates if a field is indexed, only that tool tip which is just sooo slowwww.