There is a way to add specific attributes to a Custom product type via install script like this:
$fieldList = array(
'price',
'special_price',
'special_from_date',
'special_to_date',
'minimal_price',
'cost',
'tier_price',
'weight',
'tax_class_id'
);
// make these attributes applicable to products of Custom Product type
foreach ($fieldList as $field) {
$applyTo = explode(',', $installer->getAttribute('catalog_product', $field, 'apply_to'));
if (!in_array('coreproduct', $applyTo)) {
$applyTo[] = 'customroduct';
$installer->updateAttribute('catalog_product', $field, 'apply_to', join(',', $applyTo));
}
}
Is there a way to apply ALL attributes of, let's say, Simple product (with all created and custom attributes and tabs, not known at the moment of extension installation) via install script to Custom product type? My guess would be something with LIKE statement for 'apply_to' field.