You have that, when a product is on development they can change its API anytime. This change is quite important though, its related on how to set the events of your form, for example, the useful beforeSubmit.
This wiki will explain how you can use the Field range extension with multiple Bootstrap form layouts (vertical or horizontal). You maybe aware, that the yii2-field-range extension enables you to easily setup ActiveField range fields with Bootstrap styling. You basically can setup two attributes joined together like a single field with combined validation error block.
If you want to edit data directly in the gridview in a 'dropdownlist' style, then you could use the 'type' => 'select' option of TbEditableColumn (YiiBooster) or EditableColumn (x-editable for Yii). This wiki shows how to get data from the db for the 'dropdownlist', by converting AR model data into an array that is passed in json format.