Of course it does display good.
See to create form based on params this code is used
$params = new JParameter($params_ini, $XML_file_path);
In DB in params field only ini data is stored. So it is obviosly JF cannot render form because I do not point anywhere what XML file to use to render form. Also not I cannot use config.xml in joomla root. First because it is used for other things and second I have few JF contentelements. And every element has parameters. I cannot store all parameters in one file. I think best way to solve that is to add atribute.
<field type="params" name="params" translate="1" xml="administrator/components_com_mycome/myxml.xml" xml_group="General">params</field>
This will alows to tell joomfish what XML file to use for every param field separately and yet if one have all parameters in one file separated into groups, it tells what group to render.