He went with Josh Brown, a HELOC specialist I’ve worked with in the past.

With that being said, do yourself a favor and do the research yourself on zoning, valuation and ACTUAL rent before talking to STR specialists who make a living on selling these =) Just my 2 cents...

Worth a discussion if you want to send me a DM I can connect you with my team’s DSCR specialist.  

OR do you call each individual specialist (plumber, electrician, mold expert, etc.)?

You may want to speak with an asset protection specialist. 

You can not call the specialist or doctor directly but their board information or business info will be registered with the state.

I would call or email a specialist in FIRPTA such as "Tax solutions FIRPTA consulting" in Katy Texas, since they can answers all questions about the law plus investor friendly lenders

I really need a CPA or tax specialist that is an expert on Solo 401K's to help me out with this.  

Private money lenders or construction loan specialists, on the other hand, are faster and more flexible, though their rates and terms will likely be less favorableFor a more rural area, local banks will almost certainly understand the market better, but connecting with private lenders who specialize in spec homes could provide more agility.

Not sure how common or widespread that is, but it has happened.