I would add to this that it has historically been pretty accurate, up until the hole that nobody knew about hosed the coin. Once the fix was made, the steady progression of stakes had been interrupted and a whole swarm of stake ready wallets hit the network all at once. There were a number of unforseen problems with this, most of which were FAR more troublesome than the nvcs adjustment. Besides, it's likely to return to normal levels *IF* we all use coin control to spread out our blocks. Consider it incentive to not be lazy.
I will tell you all the issue. It is simple.
This one line was changed: https://github.com/maxxine/TEK/blob/master/src/main.cpp#L39
The base difficulty was lowered as part of the fix.
This allows/causes a few things.
1) Easier/lower CPU intensive staking
2) Easier chance of attacking with PoS
3) Lower stake reward, as now the starting point of the reward calc is much lower (see here):
https://github.com/maxxine/TEK/blob/master/src/main.cpp#L992-L1006 The chance of this going back to this difficulty are low, therefor the chance of getting the full reward (500%) are also low..
This can not be changed again without a hard fork.