Not only is it rarely compensated, it's rarely effective.
Software work is bursty and creative, not mechanical and hourly.
you are lucky to have lived a career where that is true. it is largely true in the states and sometimes true in startups. there are corners of the world where it is less true than one would hope.
I think the occasional burst of activity can and does work, but it’s a budget you need to spend strategically and let it recover. Constant 996 indeed won’t work.