I think nothing will lift aggregate RE prices in the short to medium term. Anyway, you don't want to hedge your upside risk, right? If indeed rates go lower still, you'll lose some on your puts, but you'll lose much, much less, at a much slower rate, than you will gain on the puts if interest rates rise. That is a decent hedge, and about the best you can do, I suspect. *You might also consider some creative ways to structure your ownership of these properties so that you have some downside protection on entry. It is a buyer's market, so maybe you can get the seller to give you some type of put option to accompany your purchase. That would be an ideal solution I think, but it is a bit out of the box and you'd need an open minded and motivated seller. An example of a put option would be thus: If a house on the same block sells for 20% less than your own within the next 18 months, the seller will reimburse half, or 10%. You might structure such that you could withhold 10% of the purchase price for 18 months as insurance. Again, it is a buyer's market, so perhaps it is an idea worth exploring.
If rates go lower and RE prices go lower, the hedge has failed to provide what the OP is looking for. To my mind, this scenario wouldn't even be in the realm of 'surprising'.