DROP TABLE and autovacuum

If we tries to drop the table on which autovacuum is running, we have to
wait finish of the vacuum. However, the vacuuming effort goes to waste for
the table being dropped or rewritten. Meanwhile, we've already had the
autovacuum killer triggered in CREATE/DROP/RENAME DATABASE commands.
Can we extend the feature to several TABLE commands?

One simple solution is that every time a non-autovacuum backend tries to
access a table with a lock equal or stronger than SHARE UPDATE EXCLUSIVE,
the backend checks whether some autovacuum workers are vacuuming the table
and send SIGINT to them.

Is this worth doing? Or are there any dangerous situation in it?

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center