@zensaiyuki I find it interesting that these benefits & drawbacks can vary a lot between different configuration options.
e.g. letting users set the (default?) font for websites can both help accessibility, and is trivial to implement because it's just a "magic number" used during rendering.
@alcinnz also, that option doesn’t otherwise change the behavior of gestures. the example raskin uses is the configurable toolbars of some 1990s versions of MS Word. convenient if you’re a power user, but now you can’t document those shared installations (households, libraries, schools) of msword for novices because the toolbars could contain literally anything.