Don't know if this will help but I ordered the smoothcast 45D series from the as they
said it would dry solid but not require a pressure chamber to rid it of bubbles.
While it does come out bubble free, I have as of yet been able to get it to dry
solid. It dries like your army men look. Just a though. This was from smoothon
It also depends on the size and shape of the cast item. I used one of their rigid plastics for a part that is long and very thin and it still flexes a bit.I think maybe you misunderstood there info. I does curesolid, I does not cure rigid. It will stay simi flexible for its lifespan. I have used this material alot for miniature sets and props and its wonderful stuff.
Its important to check if a material if rigid or flexible when fully cured before you purchase it.