Have about 50k I would invest (access to more), with excellent credit and good income too, from my full time job.

He is critiquing products and courses that he hasn’t personally used.

Oklahoma is excellent for flipping, as well as for buying and holding. 

I prefer building my own spreadsheet on Excel and fine-tuning the specific expenses myself.

The interest rate is 2.375% so I am having a hard time letting go of the excellent rate.My question is: To scale from here, should I sell it and buy a fourplex as a house hack? 

Which is also one of the 3 fundamental needs of a business most often (customers, product/service, place of operation). 

Or, is there a manual workaround like keeping track in a Google Sheet or Excel?  

There ya go, that's productive vengeance. 

Your advice about understanding the underlying accounting and how the numbers are generated is an excellent point—I can see how that would help me identify any gaps or inaccuracies in the financials.I also really appreciate the insight on how T-12s differ based on the number of units.

Great tools that get updated regularly.I am on the lending side of things and would be happy to hop on a call with you anytime to discuss financial strategies and help answer any questions you may have about nearly any loan product available to help you on your journey, even if they are not products my capital partners offer.We are all here to help you learn and grow.