It depends on how well the SN can handle a huge volume of submissions...but I believe it will have to do this either way.

Yesterday, I submitted a job that had an issue which allowed every pass of the interpreter to find a "Bounty", so the miner tried to send hundreds of submissions pretty quickly....this is something anyone could do (i.e. create a simple job that allows legitimate bounty submissions to spam the SN).

So I thought your original design had a small fee on each of these submissions, along with the announcement in order to deter this kind of behaviour.  But if you have another approach that simplifies things, I'd be all for it.