Yes I definitely recommend this, get your friend to bring along
all the proper documentation and letters he can and see the chief
tester.
I had my test date 2 weeks before I was scheduled to leave
Singapore to go study overseas, and I failed the first practical
test. So I saw the chief tester with my dad and made an appeal to
get an earlier retest since I was leavin in under 2 weeks, and he
was able to get me another test 3 days before I left the country!
Lucky I passed that time 