Note that a truly self-directed Solo 401k would be exempt from UBIT on leveraged real estate. 

Wife and I are both self-employed so acquiring a traditional mortgage is challenging based on our "on paper" income.

But are you saying to find a local bank branch and physically go in and develop a personal relationship with a banker? 

My first STR, and plan on splitting between self use and renting to help offset costs. 

Begin with the end in mind and work backward to develop a roadmap for achieving your goals.

If you're not using Hard Money and the property won't qualify for conventional financing, then you'd probably need to locate private money or if you have friends with IRAs, they can be self-directed to invest in real estate.

Managing self-employment income requires tracking eligible deductions like business expenses, home office use, and retirement contributions.

I own a duplex with my husband and have been self managing the rentals (one is MTR and one is LTR) under my LLC.

For a number of years the majority of my time has been devoted to investing and developing.

I would love for you to try out, it free.And the best part is, I am the developer, you can directly ask me to incorporate any features that can be useful.Link: https://apps.apple.com/us/app/sparrowlane/id6741719361