Right now, the friction to reducing a pledge cap can be quite high in practice, since it often means first reducing the pledge, waiting 7 days, and then remembering to reduce the pledge cap, too. Why not allow the pledge cap to be reduced below the current pledge, in which case both the pledge cap and the pledge are reduced to that amount after 7 days?
Ideally, this would allow me to reduce the pledge cap as low as I wish, not just one level back, effective at the end of the akrasia horizon.