The multiselect component has an option of “allow user defined values” in addition to the allow custom values option, and they behave slightly differently.
Allow custom values: if the .value of the component is not present inside of the array of options, display it anyways. This could be set by .setValue or the initial value setting of the component.
Allow user defined values (multiselect)- users can select their search value as an additional option. Allow custom values doesn’t need to be enabled for this to work at the moment
We definitely need to add the same Allow user defined values functionality to the dropdown, at the moment the best workaround is to set the values array to something like
[1,2,3].concat(select1.searchValue) which would add the searchValue (the user input) to the array of options to select.