You mention using the funds as a down-payment on a property. 

To be safe, consider starting with standard percentages or slightly reduced figures until you have reliable data on the property’s performance.

Just to trim a massive tree on one of my rentals is $4,750.

Then you can read a more in-depth book like The Book On Rental Property Investing by Brandon Turner or The Unofficial Guide to Real Estate Investing by Spencer Strauss.2.

Expected to hold 3-5 years and then sell for nice ROI (greater than 35% cash on cash return).

Are you building on slabs, crawlspaces, or basements?

But you can't stay on title. 

Ask the seller for repairs or walk away.

This comes with some other ramifications around legal liability and the ability to get a mortgage on the property.The other way to fix this is to create an LLC now, and both you and your MIL contribute the current properties into the LLC, then the LLC 1031 exchanges the old properties into the new property.

We have been swept by the influencers touting the benefits of cost seg, so we are wondering how come nobody ever mentioned that it might not fully appy during the first year in service.You relied on two almost equally awful sources of information: influencers and IRS publications.