These asset backed loans are just regular loans with lower interest rates. So instead of getting $50M @ 11% they can get it at 4%. That's the extent of the "hack".
They then keep the ball rolling by refinancing at each expiry and just paying the interest (and hoping their assets maintain or increase in value)
Eventually those loans will need to be repaid and the money will need to come from realizing capital gains.
So if anything its a tax deferral scheme with a low interest rate and elevated liquidation risk. Which all raises the issue of being taxed twice on the same money. Taxes once when you take the loan against it, and taxed again when you realize the profit to pay the loan.