If all your concerns are covered, do the numbers still make sense or should I see something else?

More and more insurers are refusing to cover disaster-prone locations.

If one or more units are vacant, the remaining units often don’t provide enough cash flow to cover expenses, making it harder to meet operating costs.Maintenance costs: A fourplex comes with four times the appliances, plumbing, HVAC systems, and other components to maintain, leading to significantly higher repair and maintenance expenses than single-family homes.If you want to see the detailed calculation, read this BP blog - More Units Doesn’t Mean More Money—Why a Single-Family Home Can Beat a Fourplex.Resale value: Multi-family properties have a limited buyer pool—mainly investors—who base their offers on CAP rates.

The website looks like it covers all of this, but I haven't seen a lot of talk about it.

I’ve seen people buy land thinking water was covered only to find out they had to pay 6 figures to get water re-routes or upgrade pump stations.

The house had a warranty the first year that covered anything that came up, and we only had one issue with HVAC over those 3 years. 

They’re built for heavy use and have faster drying times—usually 30–45 minutes—without needing major electrical changes.If you’re up for a bigger investment, adding extra stackable units in the garage could be a great long-term fix, though it’ll mean some electrical work and setting up proper ventilation.I’d probably go for the commercial upgrade in your current space first—it’s quicker and might solve the bottleneck right away.

You can cover the wire mesh with drywall patches (they tape on wall and across the wire, white/paintable, different sizes) as the wire mesh is what will prevent the rats from eating their way into the property (the covering material is cosmetic only).

It's just an unfortunate side of house flipping when you're first starting out - you typically don't have your downside covered.  

.)- All in Cost = Cost to build * Square foot  - Sales Price = All in Cost + (All in cost * 20%)* Covers contractor and soft cost on either fee based or cost+- Profit = (Sales price - (Sales Price * 7%))* - All in Cost   accounts for agent fees and closing cost- Initial List Price = Sales price + 10%      A buffer to test market absorption- Break Even being All in cost, point where everyone is paid except me. - List price is to test the market absorption at "x" price. 250k land + build.