I don't think such a high ratio of rent reimbursement to income would pass unnoticed by Inland Revenue.
Your employer has to exercise proper control over the reimbursement, and part of that control is how the level of reimbursement applies to ranks / position - ie your 34,000 would have to be standard for all employees earning 50k per month, and those in higher positions should be receiving higher rates. I don't think the IR would find such a high level as proper control by the Employer.
Also, there is an article that says:
Also important to note that if your income is set that low, then your bonuses, salary increases will be based on that. So if you get an extra month as bonus, you would receive 29k instead of 50k etc.Points to note:
Where the taxpayer is a high income earner, then applying 10%, 8%, 4% would have a reverse effect as there would then be an excessively high amount calculated as accommodation provided/reimbursed by the employer (evidenced by comparing rental value with actual rent paid on the property). In this case, a notional/rateable value is instead obtained and added as the rental value of the accommodation. This notional/rateable value is found by looking at the assessable value of the property where the employee is residing (the rates notice).
All in, I don't think your plan will pass muster with IR, or indeed your employer.
Tax Series Part 4 - Hong Kong Housing Benefit | Star Anise