arpadveress 
It is a possible way forward.
Manufacturer may apply for it whenever 3rd party certification is not mandatory, but it makes sense E.g for marketing reasons.
Possible cases might be:
- Electrical: cat 3
- Non.electrical: cat 2 and 3
In that case ATEX Notified Body shall not place its nr on the certificate, E.g NB 2684. Which means not immediately a failure at the time of inspection.
Keep up good work.
Arpad
