Clicking on a value to fill into an `array` query parameter replaces existing value(s) rather than appends them

[jnicholls]

See screenshot above. When clicking on one of the "Allowed" values to fill in an example value to the parameter field that is an array type (add-multiple is enabled), I would expect the value to be appended to the list rather than replace existing values in the list.

Is there a way to configure this behavior and enable appending the values rather than replacing? Thanks in advance!