I actually do like designating thousands of stones to be dumped. The quantum stockpiles make it all look so great when it is finished, I train the masons up with making stone blocks all the time, and I have loads of raw material to pave the world. Waste not, want not! I am rewarded for the micromanagement by an unblocked view of the floor engravings.
Big projects, constructions or digging, are difficult because they are time consuming. Dig out an area in sections. I find it easier to designate 50 stones for dumping over the course of a year, than designating 500 stones in one day. If it is about materials used in workshops, use "designate forbid" on the to-be-dumped-later-stones. More haulers = more dumping done. I don't try anything big with that starting 7. When I have about 20-30 idlers, it is a perfect time to work. Still difficult for people who run a huge military draft.
Mass construction is the same as mass dumping. Go to my refuse haulers, disable everything but masonry. Make sure there isn't an open mason workshop with an order issued. Then those 20 idlers go place my 20 floors.
Now, I won't complain if changes are made. I like the Designate To Be Dumped Idea. But I think the time invested in hauling and dumping excess stone is well rewarded by an orderly looking fort nowadays. I am golden as long as quantum stockpiling sticks around.
(Does anyone else mine out soil layer walls and replace them with constructed blocks just for looks, or am I just crazy? lol)