For listbox as requested from @dedmen

disableSerialization;

_display = findDisplay 313 createDisplay "RscDisplayEmpty";

_lb = _display ctrlCreate ["RscListbox", -1];
_lb ctrlSetPosition [0,0.06,1,0.94];
_lb ctrlSetBackgroundColor [0,0,0,1];
_lb ctrlCommit 0;

_text = "Some Entry";
_data = "SomeData";
_value = 1337;

_fnc_fillLB =
{
  for "_i" from 0 to 20000 do
  {
    _index = _lb lbAdd _text;
    _lb lbSetData [_index, _data];
    _lb lbSetValue [_index, _value];
  };
  lbClear _lb;
};

_time = diag_tickTime;
for "_loopCount" from 0 to 1000 do
{
  call _fnc_fillLB;
};

systemChat format ["Time passed: %1", diag_tickTime - _time];

I forgot to close this.
Back then I decided theres nothing to optimize and that most time is actually spent in the script side.

8% time is spent in lbSetData, 6% in lbAdd, 5.5% in lbSetValue.

15% is in reading script variables
11% assigning script variables with = sign.
10% in checking types, when you call the lb* methods, verifying that the types passed into them are allowed for the script commands
8.3% in creating arrays
9% other overhead in executing script commands
5% for the for loop transitioning to next iteration
4% entering and exiting the scope in the for loop

63% just for the script loop.
19% for the lb commands themselves.

And the rest are rounding errors in my profiling data.

The lbAdd itself is 6%

But... I was able to find some other optimization making all scripts faster.
That got this benchmark from 20 seconds down to 18.5. Smol steps