If you have "cure" for "problem" I described, I assume that all miners of DTC would agree that must be first patch or fork.
Unfortunately I don't have cure for it.
But I don't think it is important problem.
Coin must be designed for constantly increasing popularity and difficulty and for long time distances.
Such variations of difficulty in scale of days (and weeks, may be month) it is a small noise. Sorry for this my opinion.
May be block reward must not be defined by difficulty.