Tsangan kits carry different sized keys from a moogle. On the Pure and Race, the modifier keys are different sized compared to the modifier keys on for example the Poker. And the Noppoo Choc Mini has different sized keys as well. So basically a Tsangan kit will be a set that is made with whatever size keys that particular group buy is after.
The main keyboards off the top of my head with different sized modifiers are; Choc Mini, Pure, Race, Phantom, a lot of Korean keyboards, some custom keyboards.. but most common brands like CM and Leopold and Filco use regular sized modifiers, so no Tsangan kit is needed.