Someone mentioned this in a chat and I'm wondering if it's a real thing. I've experimented and haven't got it working consistently.

Basically I was told that if you have autodig on, a high max idle time, and say 4 multilevels going, you could wait until the dig was over with no open level, open a level that's been idle for a day+, and it would use that idle time retroactively with autodig, so you can significantly speed up digging time by effectively digging in parallel. Obviously this is late phase 4 digging before a SA.

Except I haven't gotten it to work Has anyone done this successfully? Did it work once as a bug and was fixed?