Sometimes I need to navigate inside a long script. I have used the code sections and outline view which helped a lot, but cannot really jump to precise location back and forth easily.
The feature "previous source location" looks promising by name, but it seemed that only remember the last location in each source file, not different locations in one file.
Of course the location history inside one file is not obvious. User could edit some lines in some place, jumped to another location then jump back etc. I think the useful concept here will be the scroll history, i.e. "view" of current file, not just line number (user could edit in one page across different lines, but it's still same view/page).
If RStudio can remember the different view/page of the scroll history for source file, it will help a lot in navigating. And giving the back/forward button a list of history (just like many browser back/forward buttons) will be even better.
Of course this is not needed if I have kept the source file small. However with Shiny app sometimes to split a big file into more files have more disadvantages than advantages, so I still need to maintain a long file (3000 lines with a lot of features put into package functions).