Two months before each lease expiry date, the practice of an agent I know is to offer a rent increase of $x if the tenant signs up for a similar term or $2x if they don’t commit to a term. That seems less cumbersome than tying the figure to any sort of tax deductions administration complexity.
Given the increasing burden of land tax, not to mention the opportunity cost of not putting or keeping the money in the bank, contrary to what many people think, all the tax concessions do is attempt to keep private landlords (are there any others?) in the market. Keep sticking pins in them and see what they do.