Hi once again at your doorsteps

I was wondering is there any way to make smon obey you.
Here's the problem I faced

A delete statement was fired from a session, which ran for a long time (2 1/2 days) before it was killed.since there was some rollback being done, so the OS process was also killed.
And then the developer felt the need to tune the statementand eventually came to me
The tuned statement was fired and it was seen that it's waiting for for an enqueue held by SMON.Obviously SMON was doing the pending rollback from the first statement.Is there any way I can make SMON work faster or give up the rollback?? What could be the consequence of this?