Create ASN (archive serial number) as autoincrementing Metadata

According to the docs, one should manually add a ASN via the custom Fields function in the UI. This has some "problems":

1. I need to know at which ASN i stopped last time when adding a new one to an additional document
2. I cannot easily search and order by ASN
3. Currently there are much more steps necessary to achieve such elementar result (which results bad user experience).

Coming from Paperless-NG, one has a metadata field for the ASN which is empty by default. If i decide to archive my scanned document, i just press the +1 Button and the Backend selects the next ASN-ID and inserts this into the field (then i just press save after noting the number on the document).

The ASN should be an Index / from an indexed Table. For example: If i create an ASN (e.x. 12), save the document and exit and delete the ASN later because i dropped the physical copy (i don't need it anymore), the next number generated should be 13 not 12 (even if 12 does not exist) because it is "reserved" by the dropped hardcopy.

I hope my point is understandable :)