Lockable Render Slots
An option in Preferences to throw a warning when attempting to render that an image is already in a render slot, and ask if you would like to proceed anyway. I have had enough mishaps where I accidentally hit the wrong hot key, or click the wrong button in the Compositor, and my 2hr render is written over.
2 Comments
It would even better if blender rendered an image to a new slot automatically without the 8 slot limit. Cinema 4D does this and you can save any rendered images as long as you don't close the project.
Yep, having this in base blender would be very nice.
Free kekit addon has auto advance for render slots after render, but it adds way too much other stuff if you only interested in render slot part.
There is also this paid addon , not sure if it's still works though since it was last updated 4 years ago.