Extended Expiration?

I'm considering making some modifications to the
ACTION_EXPIRED_DATED.  I've been getting innundated with SPAMS using
dated addresses that expired over two years ago.  I'm assuming that
they've been culled from USENET.  My thought was that I would create
two tiers of expiration: EXPIRED and ANCIENT, so that you might have:

ACTION_EXPIRED_DATED = "confirm"
ANCIENT_LIFETIME = 30d
ACTION_ANCIENT_DATED = "bounce"

What would happen is this:

After a dated address expired, but before ANCIENT_LIFETIME,
ACTION_EXPIRED_DATED would occur.  After ANCIENT_LIFETIME,
ACTION_ANCIENT_DATED would occur.

Before I do the work on this, I was wondering if anyone (other than
me) thought that this would be a useful feature and if so, what the
probabilities would be of getting it incorporated into the codebase.

Thanks,
- Mark

P.S. I'm glad to see that TMDA has had some new releases.  It's too
     good a piece of software to stagnate.