short sale closing before seller move out

I have a short sale will close before the seller move out. I know it is better to wait till the seller moved out then sign the closing document. But, in reality, there is lots of cost or issues if we can not sign the closing document now. Loan's lock rate will expire soon, short sale approval letter will expire soon (already extended more than a month from original), etc. I let title company prepared an addendum for conditional closing document (signed by seller). All document will not be effective untill I verified the seller move out (seller vobally said to move out by certain date).

Is this a practical way to handle these things? I saw several people asked this situation before. I hope this is a more practical solution.