I and I suppose we have never looked at it as a single strategy. BKW and SOL have increased their dividends over the years. Essentially they have paused dividend increases but most of the time it is a slow creep. So I don't feel any issue to hold shares that can service their own interest and as such after franking its around 4.5% and you can borrow at 3.5%. You may want to look into the way you go about it as you cannot just deduct your mortgage interest. So you need to borrow money to own shares and that is why people go into margin lending. You may have to do it in two steps - margin loan to pay off the mortgage then a few months later borrow the money through the mortgage and pay off the margin loan.
If you said to me borrow money to increase your holding in ACF ... I would be more concerned the risk profile is much higher as would be a stock like TPM. So, in that case, I would not be borrowing to invest in less certain stocks ( more risk around profits and dividends). I /we used loans to borrow for widows and orphans shares - The SOL, BKW even EVT and more recently CCP.
However having said that - when I got involved in this I needed to borrow heavily to not end up as a minority without any say as the others had far more resources. So I have over time used my income to p[ay down my risk. If you said to me is this the time to borrow - we are either at the beginning of a new bull run where low-interest rates get baked into valuations as do low expected returns or we are near the end of the current bull run.
Right now I am accumulating cash... As you said this is an opinion and not professional advice. To illustrate I would rather borrow so as not to sell BKW /SOL but would sell ACF if I had to rather than borrow to hold it. We would sell the stocks if the interest rates climbed and we had to fund more than 1% differential.
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