If I were you, I would look into the HELOC to access your additional equity.

I'm not the most diligent reader so that type of info is crucial for my style of learning. 

Additionally, the schools for this neighborhood are excellent.

I do however, think that it would present a very unique opportunity for a buyer with children whom wants to relocate from the city (easy commute in) and perhaps have additional rental income, OR move the in-laws into the ADU. 

In addition, try to network with a realtor who may have some buyers that had deals fall apart.

In addition to the educational components you mentioned, I suggest you network with like-minded investors locally to you and in the areas where you plan to invest. 

Does UMMC offer any incentives in addition to Live Near Your Work?

My lender showed up to my closing to support me ... old school style LOL Mr.

I could easily put in an additional 30k or so and purchase something in the range of $800K.

A full review is required when a primary buyer is putting less than 10% down or when an investor is putting less than 25% down This review requires a long form questionnaire, budget, by-laws and possible a couple additional documents.