Memory Management

I have been really pleased with how much code I can load/run within 48K ram. My current project is getting quite large yet when using minification I still have room for 700 variables.

I would still like to ensure I use as little memory as possible (just in case I hit the limit).

Minification works really well but for those variables that the minifier cannot rename i.e. those that interface with the object (at root level) what length should I try to keep variable names to?

i.e. what are "Short" variable names - I saw this mentioned somewhere but can't find it again?

If I have a module defining an object/class of which there will only ever be one instance, is there any benefit (or overhead!) in having all functions against the objects prototype?

I also tried placing all my main code within onInit(). i.e. instead of:

var aaa, bbb, ccc;

function one(){
}

function two(){
}

function three(){
}

onInit(){
      one();
}

I used:

onInit(){
      var aaa, bbb, ccc;

      function one(){
      }

      function two(){
      }

      function three(){
      }
    
      one();
}

This allowed the minifier to rename most of my variables/functions but resulted in more memory being used - why did this happen?

I have read http://www.espruino.com/Internals but not 100% sure about the best approach.

Any other ideas on how to minimise memory usage yet keep my code readable/maintainable would be appreciated.