1. The specification can not be imported due to errors in the code admin_import.php. One of the bugs - update_items_features function uses the variable $column_value, which has an incorrect value in the function call. Most likely, instead of $column_value function should be used $col_n (see loop in lines 898-927).
2. Unable to import several specifications, as in the table can be assigned to only one field from a file (see pictures).
3. After eliminating errors show an example xml-file to import several specifications.

It took more than 3 months... Developers, you are doing something?!