Highlight relevant rows that are still on screen

[Masterhigure]

Some times you are inside a block where the top of the block is still on screen. I would very much like the possibility to highlight those lines as well, just like the lines that are technically off-screen which this plugin brings back on-screen glued to the top. Whether that's best accessed through an option in the settings or through a separate (by default empty) highlighting group I don't know.

This is of course only relevant when mode = 'cursor'.