DKIM keys stored in sql?

[Tom Johnson via amavis-users]

We would like to provide DKIM signing for a large number of customer domains (many thousand) - loading them from the conf file isn't very practical.  We prefer to load them from a sql table. 

We are currently using opendkim for this purpose, but would prefer to consolidate this into amavisd-new.  

Is there some way to do this in amavisd- new that I am missing? Or is it a planned feature ?