Sounds like a great deal/property.

Sounds like you're putting in the work, researching, and joining the best possible forums!

How long did it take to complete those first three builds?

However, everything I have found in my preliminary search is via the auctions and it sounds like that's not the way to go.

This completely depends on what you are looking for.

However, there’s a catch—I’m looking to partner with an investor to help provide the capital needed to complete the deal (would need to raise around $200,000-500,000).

There are companies such as Cover that offers a full service ADU deliverable from design through construction completion.

I am very interested to see experienced host's perspective.That's a great point, and I completely agree—many amenities are more about enhancing the guest experience, which indirectly impacts ROI through better reviews and repeat bookings.

It sounds more like you want to do work for a short time and have success without knowing much.

Sounds like there are more than just 2 options.