Editor components like the pickers, textboxes, etc. use an internal <input> element while submitting to get their value from. This value shows up in form.serialize() even when no value selected/provided.

In Angular we want to lazy initiate the options of a multiselect. After angular loads the multiselect directive, the control does not react on changing the k-options variable. If I recall, it should be solved when the control supports the setOptions method, like Kendo UI Grid.