I have bought an investment property that had a very tight time window to close.

.- In a tight DSCR environment, insurance is becoming increasingly important.

I’d maybe start with, I agree with $x amount even though you missed the deadline but expect the rest returned to me within x days, or I plan to contact tenants rights group to help me seek all damages allowed.

As to the actual construction, time can be saved by ordering materials in advance and put in storage, having multiple crews going at once and having tight timelines. 

Tell them that if they fail to meet the deadline, you will hire someone to clean up after them and they will be charged.5.

Most of those claims to pay if not closed on time have loopholes/tight requirements and more often than not we have seen the fall-out.This is a lot I know haha but hope this gives some context.

I literally financed 10 properties without a job back in the 2010’s when “credit was tight.

Being creative when money gets tight is key in your case and having a finance partner who trusted you and actually reached out to you it doesn't get any better.

They left me hanging during tax season and I had to find a tax prep company days before tax filing deadline.

Just like the rest of the house, the roof is also shifting and settling in... if they made the roof "tight" then yes you are going to have some places where corners might break or things happen.