I could explain why, but I feel that @Dave Meyer and Dan Nelson do a great job on the podcast. https://www.biggerpockets.com/blog/real-estate-1043

Better to get a job quote than an hourly wage.

It sounds like you’ve done a great job adding value to the property with the additional living space, but unfortunately, appraisers sometimes have different criteria for valuing finished basements, especially when it comes to bedrooms or family rooms.

The installer said it will be ~6-8 hours job and can finish within 1 day - but the tenant says he wants to have 1 day relocation and need to stay out of home for 1day. 

But I'm fine to put down 20% on total value (80% LTV), I have a full time job, so I can support my underwriting with the steady income. 

I recommend that you learn the tax code and take ownership over your strategy.Not having some foundational knowledge and an opinion on how to approach taxes as a business owner is a huge mistake.In my experience, every single business owner who says "I just let my CPA worry about it and I focus on my business" is doing a suboptimal job at tax planning.They are likely missing out on 10s or hundreds of thousands in saved dollars every year.Stop making excuses and get to work.Just a few months of part-time learning about taxes will pay you for the rest of your career.

 I bought my first house in 1987 and  5 years later I got a job transfer from Miami to Central Florida. 

We do a great job of bringing consistent deal flow to investors. 

Hi Jamie,I admire your diligence and attention to detail.  

You are paying them to do a job, I would let them do it and hold them accountable.