remove MuMoTcontroller._plotLimitsWidget and use the self._widgetsExtraParams['plotLimits']
_plotLimitsWidget should be handled as other parameters. It would be sufficient to put 'plotLimits' in the _widgetsExtraParams dictionary (or, most probably, in the _widgetsPlotOnly dict as recomputation might not be needed).
Does that make sense? plot limits can be seen on views that don't have extra advanced widgets... e.g. field views.
To fix #256, field plots have now extra advanced widgets Commit to come....
In my opinion, since field plots currently have no advanced widgets to my knowledge, and since this is fairly basic functionality, it may be better to have this showNoise and `showFixedPoints (issue #282 ) as standard widgets? But since you've started down this route maybe it is most consistent with other controllers' usage of advanced widgets.
I don't have a strong opinion on this.
If you want to leave it on the standard widgets, I am ok with it. But as this leads to having each controller with a different set of standard widgets, it could be convenient at least to handle them (as we do for _widgetsExtraParams) with a generic dictionary that each controller populates as it likes (maybe called _widgetsFreeParams).
If I should choose, I would put both _plotLimitsWidget, showNoise and showFixedPoints as advanced stuff.