Well, the Jester series was launched 20 years ago, so it wouldn't be a big surprise if they did some (in hindsight) strange things in the software...
As a software developer myself, I read "this is a complex function" more as "we didn't anticipate it in our initial design" 😉
Because, lets be real: 16 bit dimming is no different from scaling any other 16 bit value (like eg. a position) during a fade; and you obviously know how to do it, if you offer that option for some parameters. But if you approach the design with an "I enter and display percentages, so why would I use a different number range" attitude, then you will (consciously or by accident) try to make the numbers adhere to that presumption — been there, done that, happens to every developer.