Pros/cons of buyer making TISH updates rather than seller?

[Hannah Diment]

Hello- I'm closing on my first duplex is NE Minneapolis on Tuesday, and on Friday they informed me that the seller had not yet completed the updates mandated by the city in the TISH report.  The seller seems to have inherited this and several other properties at the same time, and according to them, there was confusion about who was responsible for this and ultimately they dropped the ball.  I have the option to either delay closing indefinitely until they make these changes, or it has been proposed to put a good chunk of money ($20,000) into an escrow account from  which I can draw to make the changes myself, after which the remainder will be returned to the seller.  I would have 90 days to complete these changes. It seems like a good deal to me, because I am able to hire the professionals that I'd like as opposed to if they were to hire someone to do a subpar job for less.
I just wanted to check in on the forums if any investors have done this, and if there are any unforeseen big problems I may be missing here.  
Thank you!
Hannah