Calculate limiter to not do offsets

[elden1337]

In certain cases the savings to block hvac is too small to justify the extra build up that follows in the later hours after that.

Calculate if there is such a limit that we can use to flatline the offset curve for certain days.
Might be nominal level
Might be stdev of day
Might be both

[elden1337]

Calc percentage of (max-min)/avg.
If below 1 the day is "flat" if above "pointy"

If below 1, do thresholds to lower the set tolerance, for inst if < 0.75 => -1, if < 0.5 => -2.