@Carlyle Small I been using all different kinds of arsnel to build my portfolio and other investors. Let me share about my portfolio. I have bought 3 properties in 2018, 2 from pocket listing via traditional loan using 25% down and 1 from Wholesaler with cash and cashout refi. In 2019, I added 1 more rental and 2 Owner finance to it. Rental was added because that property couldn't be sold as flip or owner finance and rental was my back up plan. We bought that property through private lender and I did cash out refi and able to use built in equity to reduce my out of pocket. 2 owner finance, 1 again private lender and cashout refi and another one full cash.
Yes, HML is one of the ways to do BRRRR. But I was fortunate to have some cash from the profit from my flips which I used to buy rentals (similar to HML) and do cash out refinance. I have found and used few Private lenders who are much more easier and less expensive than HML. You are right, you burn all your cash if you continue to do 20-25% if you want to buy multiple properties in same year.
For investors who only want to built rental portfolio and don't venture out with flips and other investments, BRRRR method using HML and Private lending helps even though it has high cost associated with it. Otherwise you need to plan and save cash to buy 1-2 rentals every year and build your portfolio which is not bad idea to start with as well. It's all up to the investors risk tolerance level.