Give them an out now and balance the cost of that against them leaving the place wrecked leaving the non-op vehicle.  

You're entering into a phase of the investment journey where you want to strike a balance between proper due diligence and avoiding last minute analysis paralysis.

Then find the perfect balance for your situation. 

Depending on how much you put down, your goal is definitely achievable.

If your objective is a given gross profit then you may be forced into doing higher risk, but less competitive and higher profit flips to achieve your goal. 

This is how I have historically achieved good return.  

This balances maintaining your current property and expanding your investment portfolio, although it involves higher mortgage payments.Given your goal to minimize your ex’s financial benefit, selling your current home and purchasing a new house hack might be the most straightforward and financially advantageous route.

Ensure major decisions are made jointly.This setup balances the partnership and fairly rewards both contributions.

low cashflow high appreciationNotes purchased in the secondary market at discount to remaining principal balance have the built in capital gain profit with potential for greater ROI thru early payoff or early PARTIAL paydown.  

I would request that you stop giving immoral advice to our new landlords and stop also giving them ways to circumvent the law to achieve these goals.