Admin subpage show specific fields as columns

The admin subpage shows only the first 4 fields as columns of a form and then adds the form date as 5th column.
I have several forms where there is hardly any identifiable fields in the first 10 fields of a form.

As a temporary workaround I changed line 154 in public function get_columns() in inc/admin-subpage.php
from
if ( sizeof($columns) > 4) break;
to
//if ( sizeof($columns) > 4) break;

So all fields are shown as columns in the admin subpage. This might impact performance though. Alternatively to commenting out that line, I could change 4 to a higher number, but since it is global change for all forms, going for showing all columns seemed wiser.

It would be nice if some cf7db parameter in the CF7 form can be added, so you can specify which columns must be shown in the admin subpage. But this might mean quite a bit more coding.