Krita + GLSL - A viable way for Krita to use the GPU?

Hello everyone,
Recently I was reading the blog post about the future of Krita’s renderer, and how it will stick with OpenGL for the foreseeable future, going as far as porting ANGLE to Qt 6.x.
This got me pondering, while being constraint to OpenGL, there is any immediate and simpler way to use the GPU in more active ways inside Krita?

No OpenCL, because obviously it isn’t simple and I think no one wants to open this particular can of worms. OpenGL as far as I know is an API for rendering, so not only there is a problem with sending data from Ram to Vram, and vice-versa, also there isn’t much it can ‘compute’ in the sense of a panting app.
However, for some reason I remember about shaders and how they could apply effects to a already rendered image.

So here my question: Can Shaders be used to modify the viewport on the fly? Maybe as in Filter Layers. If it is possible would still be more advantageous then the current implementation?