Error on dispose of control that is not added to a panel

In this playground example, I create and dispose a simple slider, without attaching the slider to a control panel. This produces an error because this._host (where the attached control panel is referenced) is not defined (see controls.ts line 1364). Should line 1364 first check if this._host is defined?

For context, this error has come up for because I have sliders that are only visible and attached to a control panel when the relevant mesh that they control is selected but the mesh they control can be deleted even if not selected. I can provide more details if considered relevant.

Thanks very much!