I have that stand as well. It is rigid. The only flex should come from the board, and S.R. Smith's compatible boards have little bounce apparently by design. My board, which I'm in the process of replacing, is 8 feet.
I just managed to get the board off, and discovered the fiberglass stand was filled with water, algae, gunk and the hard rubber strip that should have stayed attached between the front end of the stand and the board. The hardware attaching the stand to the cement deck is very corroded so I'll opt to keep the stand for now. For reference, the pool was built in 1982, I purchased in 2017, and I don't know when the board and stand were installed. I mention that the stand was filled with water because in the course of researching replacement options I saw one owner stating he put the electrical junction for his pool light inside the stand, obviously a dangerous idea given what I discovered.