The degradation of catalysts during a reaction is commonly the Achilles heel of catalysis. This problem has an even more profound impact on switchable catalysis, as the switching process introduces additional possible degradation pathways. Therefore, a judicious choice of the most compatible external stimulus may be the key to successful switchable catalysis. In addition, mass transfer slows down the overall reaction rate and is influenced by the distance and diffusivity between the two catalysts. Therefore, if the physical location or diffusivity of the catalysts is not well controlled (stirring, solvent, temperature, etc.), these can lead to irreproducible catalysis.