This is already possible per Selective Blender from wwmaze. Works in a limited way. Maybe it could be set up in one preset.
Keep it in mind.
The setup would be a folder with Selective Blender blend mode 4 and 100% video b. Inside a "track a" with the clean video and a "track b" with the same video but also a video processors with blur. "Track b" needs also a black and white filter, a contrast adjustment after the blur and finally a color invert.
Here an example with an increasing amount of blur. (But 0.1 real time render.)
Greetings
Eli