Honestly it sounds like you're trying to reinvent the round wheel with a square wheel here.

I know a lot of investors from the west coast in California and Seattle, WA are investing in the midwest due to the strong cashflow and appreciation.  

That being said, I have seen a couple of examples near my area where the main home is large enough with almost 2000+ square feet and multiple bedrooms and bathrooms that her family can live comfortably in while the other unit was a bit smaller and help offset the expenses. 

Are they all the same square footage also?

If the daylight basement is being rented as an STR, can you still take bonus depreciation on the daylight basement square footage if it is 48-50% of the total square footage of the home?

My take on this discussion is this:Anyone can take whatever time and effort they want to argue that it doesn't / can't work (it does / can), or you can just do it and enjoy the benefits.It's not applicable to every situation - stop trying to force this square peg into a round hole.There's no "secrets", no "magic" to it.It's meant for situations where the way it works can help someone achieve their financial goals. 

As you do this more often, you'll be able to keep a spreadsheet of per square foot prices for materials and labor to get things done and you'll be able to estimate this yourself.

This inline space is 3085 square feet which limits the options on tenants. 

No new square footage is added in converting the common living spaces to bedrooms.

The closing attorney or Title company may be the determiner for an answer and usually at this point in the process as an agent I'd defer to them.As an investor, I think I'd want all this squared away before closing so maybe check with the attorney/closing company.