From your quote, I assume you already read this document:
The Kaltura search API does have certain limitations, including the one you mentioned, as described in the above document.
However, quoting from the same document:
Kaltura supports a partial wildcard search. You can append a search word with 3 or more characters with an asterisk * at the end of the word. For example, searching for the string hello* should result in all words beginning with hello, including helloworld. The asterisk only works as a wildcard at the end of a term. It cannot be used as a wildcard at the beginning or in the middle of a term.
So, while searching for “empo" will not work, searching for "Tiem” will.
There are no plans to change this at present time but should that change, the documentation will of course, be modified to reflect that.