ModelAdmin - SS4.4 custom filters no long work from documentation

Questions
3

So I was able to try some other things - Essentially I have the following now -

DataExtension for model admin class- update search context

    class FormRequestAdminExtension extends DataExtension{
        public function updateSearchContext($context)
        {

            $context->getFields()->push(DateField::create('Created:GreaterThanOrEqual','Start'));
            $context->getFields()->push(DateField::create('Created:LessThanOrEqual','End'));

            return $context;
        }
    }

Model Admin getList

    public function getList()
    {
        $list = parent::getList();
        $params = $this->getRequest()->requestVar('filter');
        $filters = $params[$this->sanitiseClassName($this->modelClass)];

        if($filters){
            return $list->filter($filters);
        }

        return $list;
    }

This filters the data fine now as I would like. The only thing is the export button now doesn’t respect this search context. Anyone know how to get an export of just your search results in model admin?