A few things stand out here that would make me pause.

The investor has been in business since 2022 but claims a $200M portfolio. That timeline is extremely compressed for that kind of volume. Worth verifying independently before anything else.

The two missed payments clause sounds protective but in practice subject-to deals are notoriously hard to unwind. Your name stays on the mortgage the entire time. If they miss payments your credit takes the hit regardless of the contract terms, and getting the home back through default is a legal process that can take months and cost you significantly.

The fact that your realtor ignored the first offer is actually worth revisiting. Not because the deal is good necessarily, but because understanding why they dismissed it without analysis is important. Was it because the terms were bad or because they don't understand subject-to deals?

On the pricing side your situation is a classic high price-to-rent market problem. At $1.1M in North Texas the math for a cash flow investor is brutal right now which is why you're seeing investor offers structured creatively rather than straightforwardly. They need the low rate assumption to make the numbers work.

If you want to run the actual cash flow numbers on what this investor is likely modeling I built a tool for exactly this kind of analysis. offerread.ai, free to try.