In the memoir class,
\showindexmarks usefully provides a list at the top of a page of the contents of (most) indexing entries for that page.
These lists appear in the "outer" margin, so alternately to the left and to the right of the main text of the PDF of a two-sided doc (such as a book draft). Which means that that you have to have a wide view of the PDF to see the marks as you scroll through.
On a laptop screen where every inch matters, it would be useful for all the marks to appear on the same side of the text, all to the left or all to the right (preferably the latter), so you can use a narrower window on the PDF but still be able to comfortably read the text and the index marks.
Is there any way of redefining a bit of memoir code to produce this effect?