I screen animals and then assign a score to determine how much to charge.

I typically use regional banks to fund my deals but my 2 go-to banks have either slowed or fully stopped investment loans so recently I've connected with several online brokers but all came from ads or they reached out to me vs personal recommendations and intros so I have concerns. 

Probably too small of a sample set here on BP, ask your lawyer or CPA to review

As others have said, you need to check the regs in the area you are looking to make sure STRs aren't severely restricted.

The property is a duplex, and he plans to give all the proceeds from the sell to his daughter.

This is under the assumption that these closing companies would like to get these done by the EOY for their annual numbers.

Here's an article with things to consider when selecting a cost segregation company.

You only get paid enough to continue.3) You don't need a dozen self-help books, all you need is action and self-discipline.4) YouTube University, podcasts, and the internet will only take you so far. 5) Book smarts make interesting conversation, street smarts make money.6) Find someone who is successful doing what you want to be doing and ask questions.

How long will it take to complete our return?

I always recommend people ask for a free cost/benefit analysis to determine if they will benefit from the study.