Be aware that the lender is going to require reserves (i.e. 6-18 months) based on the size of the portfolio and the type of tenants. A long-term tenant with an extended lease will require little to no reserves, but it is always best practice to have 9 months of reserves (outside HELOC equity) no matter the type of property. A small family home may require little to no reserves, but an office complex, industrial building or hotel will require a lot more reserves since these properties are underwritten in different ways.
Banks lend for residential investment properties whether or not the property will actually be profitable, but commercial lending inverse of that! In commercial lending, the banks verify the property is profitable and then add a person as a guarantor for additional risk reduction. Analyzing any deal on the front end is extremely important, and thankfully it's not difficult: add, subtract, divide and multiply. The trade off is that it is a lot easier to get commercial properties and investments because there's no tax returns needed. But there is also the restrictions of - you can't re-access that money without another loan. Commercial bank lenders are the ones where a person will have success getting these types of lines of credit across the portfolio.