Load a form in List PHP script ?

[Incremental]

I set up a new site with J3.2. You can find infos on it in my profile.
Sorry to insist on the PHP plugin which would allow to perform actions which are not possible with javascript.
To see the effect :

1. Log in in front end
2. 'Fabrik' menu / List Contacts
3. Ajaxify Links 'Reply PHP'
   ==> I get a never ending spinner

In my code I tried to link on a fixed existing URL :

$app->redirect('index.php?option=com_fabrik&view=form&formid=4&rowid=2');

Thanks for help, as it would be great to have in Fabrik