Avoid having an ng-if if mutiple:

https://github.com/angular-ui/ui-select/issues/217 - Is there any way to change multiple selection mode at the run time?

Instead of the accessor (in case something needs to be modified) - how about this:

<ui-select-match placeholder="{{espLookupCtrl.placeholder}}">
      {{$select.match.fields[espLookupCtrl.displaycolumn]}}
</ui-select-match>