Take into account select2 closeOnSelect property

Use case:

When using a multiple select dropdown list, each selection closes the list.
This means if there are 20 documents to add, this takes 40 clicks whereas not closing the list makes it only 21. This saves a lot of time.

Test case:

1) In studio add a Multiple generic suggestion widget with a standard query like

SELECT * FROM Document WHERE dc:title LIKE ?

2) in Custom properties configuration add closeOnSelect with value false
3) save and try to select multiple documents, the list closes after selection. The parameter is present in the page though (just have a look at the generated html)

So far a workaround is available with SUPNXP-16895 but that should be available OOTB.

closeOnSelect property is documented here:
http://select2.github.io/select2/