Hi!
I recently published these nodes: https://github.com/lquesada/ComfyUI-Inpaint-CropAndStitch/
They enable inpainting only in the masked area, thus speeding up inpainting and mapping the prompt better to the selected area.
You may want to watch the video tutorial here or link to it: https://www.youtube.com/watch?v=u5cNrumkz2w
Example workflows are in the github as well.
Cheers,
Luis.