A common solution to the problem is to hang the sled from the top beam when it’s not in use. It helps loading/unloading plywood onto the machine if the sled is out of the way. See my post in To rest or to hang for more details.
The safety chain would probably work if it hung from the top beam and was on a quick-release (like the stock chain mounting).That way, it could be disconnected while the machine is cutting. It would still be in the way for loading or unloading, but may be easier to access than if the sled was up at the top beam.