I've considered a variation of this. The base skill would remain unchanged. As a toolkit option, the GM could decide that characters using the skill would need additional Familiarities or face a penalty. For example, in a Pulp game, the Survival skill might work in all environments. In a gritty post-apocalyptic game, a character might need a KS for each climate type or face a -3 penalty. A superhero campaign would not need additional detail for Forensic Medicine, but a police procedural would.