I see a specific "cycle of failure" happen constantly with capital raisers.
You hate marketing, so you hire a "Done-For-You" agency. You pay a retainer, get mediocre results (or used car salesman copy), fire them, an...

Real Estate Agents take state RE tests, pass, get their license and then go get listings and in several cases with no formal sales training.

Subdivisions get capital-intensive fast, so the financing challenge you’re anticipating is real for most developers, even in the U.S.A few approaches I’ve seen work in similar situations:Phase financing instead of trying to fund the whole thing at once.Some lenders (private or institutional) will fund infrastructure and horizontal work in stages as lots are pre-sold.

If you have a few rentals and your budgets for expenses, vacancy, cap ex are working adding another unit isn't something you need to stress over "testing" because I always view my risk as being my portfolio as a whole not property by property. 

Curious how others stress-test their assumptions before committing capital.

Assuming you're working with a commercial lender (rather than a "consumer" mortgage lender), I suspect they may go up to 75% of the ARV, min DSCR of 1.25x-1.30x, amortization of 20-25 years, and an interest rate in the high 6% to low 7% range.I like how you're "stress testing" your model, but I'm curious about your FMR of $1,204. 

Airbnb tested you at $400 and you converted.

In my experience real estate can be a capital intensive business and we need to be prepared for these items  

The self-sufficiency test still applies, but now the numbers have a real chance.

I've just signed up so test driving it!