To maximize the life of a soap puck, do the following:
1) Never soak the puck.
Let it air dry , but drain excess water from around and or underneath the soap.
I immerse my soap in the bowl in hot water for about a minute before I shave. This helps in getting the lather more hot than just using the brush dipped in hot water. When I am done , I drain all the water from the soap and bowl and let it air dry.
My soap has never turned into shaving cream.If you want shaving cream, buy shaving cream.
Never had an issue with it myself. Sure, the water dissolves some soap but it's a trace amount.
As usual -- go with what works for you.
My soap has never turned into shaving cream.