It could impact your home equity and financial security.For a safer and more specialized alternative, consider a Fix & Flip loan. 

Move into a house that needs help on an owner occupied loan, fix it up over the next year, move on to the next.  

I've seen a few foreclosed properties around my area for less than $50k in neighborhoods where it would appear that if these homes were really fixed up they could ARV for $120k (or more).

As you said, they can’t make him sign the release.someday they’ll fix this issue but until then you need a lawyer, or a new lender, or the seller needs a buyer.Consider this a 2 on a scale of 1-10 for real estate problems.

I.e. if you have 500 million and make another 2 your lifestyle likely won't change at all and your ability to fix problems in your life won't either. 

I’m curious, what’s the most creative or unconventional strategy you’ve used to structure a BRRRR or Fix-and-Flip deal?

Rehabbers (fix and flip) and landlords cant or do not want to pay the good contractors , they think they will get the same quality work from the cheaper guys , that doesnt happen very often .When I bid a job I know I will be either the highest or second highest bid .

Investment Info:Single-family residence fix & flip investment.

At first, I want to purchase 1 mobile home to fix and flip to learn the process.

I personally dont do any of that.. every market / or most will have an active fix and flip sector or buy and hold sector the important thing to me is the operator full stop.. great operator will do well in any market and all the national data simply is noise at least at my level. ( loaning our own money and JV deals with our own money)  we dont broker or anything like that.