If the goal is income generation then the goal should be to invest money outside of your income properties to generate the maximum "safe " returns.

Some 8 Cap buildings can generate high cash flow and high DSR while other will be lower DSR and less cash-flow. 

Many people use them either as a last minute fallback when they can’t purchase any of the properties they chose during their 45 day period, or as their last 1031 exchange as they are a completely passive income generator.

Of course all markets are different dollar amounts and percentages, but I believe if you are marketing steadily, leads will come in and you can buy plenty of deals within your parameters.

Online leads are definitely a source to look into. 

Transactions take time to go from listing/buyer agreement to closing. 6 months may seem like a long time but if you're educating yourself on the business while working on lead generation/conversion you'll be in better shape than most people starting off.Another tip would be to consider joining a team.

Then I'm told by architects that duplexes are built to a different standard than three plexes, like requiring fire escapes, which by appearances change the nature of the neighborhood, often generating opposition.

I told them no and I also told them the entire month leading up to the due date is their grace period.

Plan is to reach out to brokers and PM firms in those areas to establish relationships that could lead to off-market properties. 

Meaning, quantify how much money you will need in 2 years to live off, then see how you can generate that money and which activities can get you there and see what you need to do.