it would probably be a good idea to rewrite KConfigGroupPrivate::serializeList to not take a QVariantList, but rather to use a streaming API. I.e. instead of:

void foo(myList)
{
    varList = convertList(myList);
    write(KConfigGroupPrivate::serializeList(list));
}

Do something like:

void foo(myList)
{
    var value = KConfigGroupPrivate::serializeList(mylist)
    write(value);
}

where serializeList is a template that does $magic internally to convert a list of values to a serializeable format (i.e. iterate over values, then stream them into QDataStream/QTextStream, wrap in QVariant only when needed). Note that you can then use initializer_list for the "static" lists like for QPoint et al.