Hi Thierry,
Yes, that's correct instead of deleting, we can archive it and maintain the gap in an audit.
The SAP Paper which you have shared, I am working on it from last few days hope something will come out. As our project is in pending so I have time to learn and explore.
If not then I have an option of choosing 3rd party like PBS, as suggested by Nico.
Please keep posting if you find anything.
Many thanks 
Regards,
Rahul