[ParetoOptimal]

One problem is that macros currently work even in things like the settings buffer. If you change that to GUI, depending on the implementation, I'm not sure if that stays true.

For a settings buffer, maybe it doesn't matter. However macros working everywhere in your editor as a default is quite powerful.

[alwaysbeconsing]

I don't follow. Macros are literally just vectors of input events; if keyboard navigation works, then so will a macro that replays that navigation. (It is also already possible to record a macro that includes mouse events.)