function construction - Using a held option

Woud there be an elegant way to use a held option ?

For example if I need to pass by reference several variables but I don't always need all of them, it can be useful. For example if I want to append an element to a List/Association/Dataset.

I've managed to make something work but it's not very usable.

l = {};
ClearAll@ffff;
Options[ffff] = {"a" -> Hold[l]};
ffff[x_, OptionsPattern[]] := Function[Null, AppendTo[#, x], HoldFirst] @@ OptionValue["a"];

ffff[2]
l

Answer

I'd do something like this:

l = {};
ClearAll@ffff;
Options[ffff] = {"a" :> l};
ffff[x_, OptionsPattern[]] := 
  OptionValue[Automatic, Automatic, "a", Function[v, AppendTo[v, x], HoldFirst]]

That is, use RuleDelayed instead of Rule to define your held option, and then use extended syntax of OptionValue.