Lock Viewport Resolution

Hi,

As a C4D Octane user, I grew familiar and appreciative of the lock render resolution button inside of Octane's render view. I'd love to be able to freeze the canvas and/or the result in my viewport with a toggle at any point during a Cycles render preview. Once "frozen" I could zoom in and navigate like we can in the compositor/rendered view, minus triggering an update until there's an actual setting/frame change or the toggle is disabled.

In other words, having a button to toggle lock the resolution of the preview to show the pixels 1 to 1. The way I do this currently is screen grabbing a render and opening it in a 3rd party app, it works but this feels possible with existing blender code. When you pause a render and try to zoom, you get this:

and while not paused: [expected behavior]

and here's how it works once an image is rendered: [desired behavior for render preview, with a toggle to restore original behavior]

I see a lot of potential uses for being able to quickly saving a render preview like a snapshot for comparison/reference like the function works for Adobe After Effects' viewport:

David Ariew demos it in C4D at 3:13: youtube.com/watch

I'd make an addon for this but I have no idea what I'm doing or talking about.

Thanks