I don't know how the hydrostatic-release works in a life raft, but you should look into it to avoid mistakes, such as the one I made:
I bought an EPIRB in a hydrostatic-release housing and discovered from reading the manual that it doesn't release until it's 12 feet underwater. My boat is unsinkable even if you cut it into pieces, and the maker says it will float at or near the hull-deck joint if inverted or all hulls flooded (improbable). So it would NEVER deploy, even if we flipped, sank or had a fire.
Now the hydrostatic-release housing sits on a closet shelf in my house and the EPIRB sits loose on a shelf in my boat.