Your question is very interesting. Normally the SQL will be executes when the report is run. So we use try catch in around the run() method:

$report = new MyReport;
try {
    $report->run();
} catch(\Exception $e) {

}
$report->render();

However, if you are using SQL query directly into widget at view, it seems a little more to perform try catch:

$store = $this->src("db")->query("SELECT ... ")->pipe(new \koolreport\core\DataStore);
try {
    $store->requestDataSending();
} catch (\Exception $e)
{

}
ColumnChart::create(array(
    "dataSource"=>$store,
    ...
));

Actually you can create a method to handle all try catch like this in the main class

class MyReport extends \koolreport\KoolReport
{
    protected function performSQL($sql) {
        $store = $this->src("db")->query(sql)->pipe(new \koolreport\core\DataStore);
        try {
            $store->requestDataSending();
        } catch (\Exception $e)
        {

        }
        return $store;
    }
}

and then in any widget, you can do:

ColumnChart::create(array(
    "dataSource"=>$this->performSQL("SELECT .... ");
));

Hope my answer helps.

Your question give us an ideas for centralized error handler, I will mark your post as suggestion and forward this topic to our dev.team.

Thank you very much.