If they refuse or fail to do so, I suspect the insurer will tell its insured, the lien appears to be unenforceable and to notify them (the insurer) if a suit is filed to enforce it. 

I’m open to paying the $20K to bring the mortgage current, but I want to ensure my position is protected.If the deal falls through, how can I secure my $20K so I’m not left out of pocket?

Unfortunately, this reassessment is unavoidable, so you’ll need to evaluate whether transferring the property is worth the potential tax increase.If a Transfer Is Not Feasible:If the potential property tax increase makes the transfer impractical, an alternative option is for your father-in-law to secure a Home Equity Line of Credit (HELOC) on the property.

It's in high demand so we booked in 2022 to secure our dates.

Once approved the send to QC and the file is sent to closing. 

I’m curious, what’s been the biggest hurdle for you when it comes to securing funding for your real estate projects?

Additionally it can often results in multiple additional tax filing requirements riving their tax filing costs up unexpectedly. 

You can hand them over all your information to organize at tax time and their staff should be able to organize everything and get your taxes filed.

This was the process for me:   Secure sufficient business lines of credit through Fund & Grow. 

Many traditional banks won’t touch them, and even DSCR lenders will avoid them if the build out is done prior the securing long term debt.