The reason this is even an issue is because of the few variables 1.

On paper, more bedrooms adds value but it depends on several variables like location, use of space, etc.

While you are overseas, there are a few unknown variables that may affect the performance of the your property.

If the variable fee based build isn't a possibility (cost-plus) than partnering may be the best alternative to doing nothing.

If you can't run numbers and understand all the variables like HOA's etc for condo's and including those factors along with repairs needed now & future etc as part of your calculations you are destined for failure.  

If you are looking to increase and maximize value, I would only focus on the variables that are solely value add and to give yourself the best opportunity to cash out more.

Just give true hard facts and be open about variables for them to consider in any way they're comfortable with. 

The only variable I do not know is if you need the cash right immediately for other reasons, but strictly talking ROI, you should pay the home off. 

Sale leasebacks are exciting because there are so many variables to negotiate.

However, rising inflation usually contributes to higher interest rates so, those which are looking to purchase homes, or refinance homes or already own a home but which is financed via a variable interest rate loan product, will feel the affects in a NEGATIVE way, since they will start to feel 'priced out' of the market.