You call this "sitting on my hands"?
(download for full resolution).
I went from Timurids -> Persia (now 1548 atm) and annexed most of my old neighbors. It is a huge amount of coring which has left me significantly behind in admin tech. But Persia is one of the strongest nations in the game (mind you its also a MP game) and my admin technology is catching up (note I have an admin idea as well), now that I have slowed down the expansion a bit.
Its been lots of fun.
No cheats, no mods. Just the coring mechanic from 1.4 which I believe is the same in 1.5.
I expect in the future I will have enough troops that I can use them to guard multiple provinces that have been annexed, while they are coring. Meaning I can annex more land in each war.