AFAIK, it doesn't matter if you are using direwolf or anything else, if you are directly connected to an APRS-IS server TCP port 14580, you will be receiving packets _because_ you sent packets to the server. This is by design, to support messaging.
The field called 'filter' that is sent to the server, is not really a filter, it is a subscription for additional packets to what I just described, above.
The only alternative (theoretically) is to setup your own server, and modify the code to do what you want, and point your IGate to that, but there may be options I don't know about.
Explain what you are trying to accomplish, and describe your local RF territory a bit.
There may be direwolf config parameters that can get the incoming packet count down significantly, yet I am sorry that is not what you are looking for.
I have a receive only IGate using DireWolf.? I would like to stop ALL traffic coming from the IS server that wants to be transmitted, but I don't know the best parameter(s) to enter.? Suggestions?
I know it isn't much data, but I have a future location that will only have internet via satellite, and every little bit of data counts toward (against) the monthly limit.