I am days/weeks away from trying it at my personal residence.  3500 sqft but only two people using it, so not sure how good of a test it will be. 

And I still finance land flippers all over the US.. so perk test and soil test we deal with every week on our funding's.

Why not start with a small turnkey rental property and test the water?

Once you narrow it down, start with small jobs to test their reliability and quality before giving them bigger projects.Building a solid network takes time, but having dependable people on call is a lifesaver for your rentals.

Why not test the market by putting the lots up for sale, and if nobody bites, that might provide your answer. 

Last year we began testing different places by staying in Carrillo and Junquillal with day trips to a lot of other nearby beaches. 

Your clients should focus on properties with significant equity potential and work with experienced contractors to stay within budget and timeline—especially with borrowed funds on the line.Avoiding Bad Deals - Encourage them to work with experienced agents, contractors, or mentors and always run multiple scenarios, including worst-case outcomes, to stress-test their numbers.Reserves - Advise your clients to keep a reserve fund separate from their loan for emergencies, unexpected expenses, or delays.

Just starting out and testing waters for BRRR in Chicagoland area.Any advice or suggestions regarding this?

My timeline so far has been:End of Oct 2022 - Permits ApprovedJan 2023 - Lot ScrapedMarch 2023 - Fill dirt brought onto lot, compaction tests in progress. 

I don't have personal experience with it, but when the app was first developed, I contacted the developer and put the app through a fairly robust test usage to see if it's something I would want to recommend to my clients (I'm a CPA).I think the app is great for its intended purpose and I do recommend it to my clients now (and have for about 18 months now).