I think this would be a prudent first action.If you are only going to compete on the Valley tables, change the cloth on your diamond to the slower identical cloth that is on the Valleys.
That way you will move the cue ball the same but you will be use to tighter pockets which should help you become a stone cold killer on those local bar tables.
It's rare, in my area, to find Simonis cloth on a Valley. Almost all are covered with Championship Mercury Ultra.