For huge projects (orchestral templates for example) the Logic-style "Totally Zoomed Out, Everything as Tiny as Possible" view is super handy for navigating around. Even on a 4k monitor, I find Reaper's fully-zoomed-out track sizes to be pretty large.
Also, Reaper insists on drawing Stereo peaks on the smallest zoom level, which makes the waveform unreadable. Either showing mono-collapsed peaks or just a "stuff" indicator would be way more useful, because a squashed stereo image at that zoom level gives no data.