Yes, I'm aware of unpaid present entitlement and how it works, the main issue is the ATO's interpretation of how it works and whether it may change between the draft ruling that issued in December and the final ruling that will issue in the future and whether or not the ATO's interpretation is legally correct (I lean towards agreeing with the ATO, although its hard to have a ruling that covers all circumstances as it very much depends on the trust deed and distribution resolutions).
By the way, one thing you need to consider in all this - I assume your goal is to get money to your wife as a distribution of profits from the trust - correct? Because if you do it via a complying loan will there be sufficient profits in the trust (after deducting interest) to offset the on the interest given the company will be paying tax on the interest regardless of the trust's tax position?