"If you leave before 7 years service, expect some fairly hefty deductions to the total"
Common misconception. If you leave before 7 years it is entirely possible that they will owe you MORE than what is in the A fund as they are bound to give you the legally-mandated EOSB. The "Provident" A Fund is merely a hedge against this eventual expense that they are exposed to by you and your career whims.