I think that will change in six-12 months when the apartment building boom slows significantly. 

If that is your intention the slow flip method is not for you.

My approach is to slow my decision making on big moves given the market timing.

Spending most of the “live”webinar telling stories to try connect to people’s emotions and sale them an overpriced product that works for a tiny percentage of people.

Similarly in real estate, there are common ways of buying investment properties where banks have underwriting guidelines to reduce their risk but it also slows down an investor's growth, such as seasoning periods.

Yes there are products that can up to 80% LTV for DSCR with 6 months reserves.

You can do this, but need to do it slow.

Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.

Are there lenders that will lend on the product at competitive rates that are similar to current 30 yr sfh amortization?

US population growth slows and fewer new households form, which is probably not great for RE investors; and 2. the Social Security trust fund runs out.