That is unfair on the potential check-in agent. It is not policy to through check bags on separate tickets, which is what you have chosen to book. So you will need to appeal to their good nature and professionalism to grant you something you are not automatically entitled to. Criticising them in advance may not be the best frame of mind to adopt to achieve that. It will not be the agent's fault that you chose to book this way.

And as several posters have said in your other thread about this, the chances are that you won't have any problems anyway. Be angry with yourself for booking this way if you want to, but going into it with the attitude that it will be the check-in agent's fault is unfair and likely unhelpful to your cause.