You will find that next deal, it’s simply a numbers game, just keep churning along and keep solidifying your processes.

That is all you can do, churn those puppies out at the speed of light.

What method would be the best to keep the cash flowing and keep my capital churning to achieve this goal?

Way more churn with real estate agents than with property managers, and the latter does a better job validating the former than vice versa.

That way, if the borrower(s) default they simply take the property back and hire a team of professionals to step in and replace the failed investor so the asset continues to churn out cash flow. 

I have/had a a number of slow payers in this asset class but compared to churning the units looking for a 'perfect' tenant in this price range we have found that being 'flexible' about payments is worth while.

You can very easily BRRRR and churn that LOC over and over. 

Home development (pros: good ROI, cons: not a very demanded area with slow churn and sales cycles, large upfront fees)2.

I can only assume that the article is referring to a European or Asian company then.Most stocks are moving independent of underlying fundamentals at this point in time, so I wouldn't get too attached to anything with a high-yield, real estate, utilities, etc. that become potential short-term safe havens, only for funds to later churn out of them as the dust settles.If your belief remains that people will continue to downsize and/or be unwilling to part with belongings, then self-storage would certainly support that belief. 

Once panic or even anxiety begins to churn it becomes difficult to make decisions that feel good and solid like you do ( hopefully ) when you are calm and secure.