What I know about if you have referral will be good as well. Apart from that, preparation and ad-hoc questioning will be part of the assessment on managing emotions and handling under stress.

FSO - largely handles a team of FSAS (Specialist) non degree holders

FSAS - Their team lead will be FSO lo, and then mostly work on the task given by FSO and Directors. HAHA.

Good thing is the travel allowance quite attractive when posted for overseas mission.
Negative thing is the toxic work culture between colleagues. IYKYK (score points).

Progression - It is a dead end. Unless you are a scholar or some smart ass, probably you will be ID-ed for leadership position. Otherwise, you are just an officer. By then you will already finding other job positions... else where...

It is a 24/7 to be prepared for any incident around the world, then everyone will need to be stand by for tasking and support which ever needed.