Hi again,
In htmleditor, the call chain
setValue(myNewValue) -> me.mixins.field.setValue.cal -> checkChange -> newVal = me.getValue()

will cancel any effect of setValue(value) because newVal is the value of the the textAreaEl and not myNewVAlue.
A ref to this.textareaEl.dom.value might be missing somewhere.

Also, it seems that there is no 'value' config to initiate htmleditor with a user-value.