This is a type of navigation behaviour I see in a lot of different softwares. It's quite a simple concept, yet a little tricky to explain.
What we alreay have in reaper is the possibility to zoom horizontally with a mouse drag. However, you can only zoom horizontally and even more confusingly, you do it with a vertical drag.
I think enhancing this concept is worthwhile, so that a horizontal drag zooms horizontally and a vertical drag zooms vertically, so if you want to you can do it independently or simultaneously.
Here is an example of another software, where they do it this way:
https://youtu.be/6dhZ8P0Pj24?t=67
I find this super intuitive and much quicker (in conjunction with the hand scroll) than any other way of navigating around.
I should also mention that by "drag" I mean possibly also holding down a modifier key, the usual Reaper way (as in: an option in the mouse modifiers)
Thanks for reading