@jansina So, I think the returns on the investment need to be
lower than the interest rate to "break even", assuming you debt recycle. That's because a chunk of your interest becomes tax deductible.
If you can get the same 6% return, then that probably includes your required risk premium. If you do better than 6%, that's gravy.
That's because by debt recycling, you get a 45% of the interest on the amount bonus to start with from the government.