I am using coax stub filters to keep my rigs from QRMing each other on 20 and 30 meters and one I just made from RG8-X using metric measurements seems to be the most killer so far. I see no QRM on 30 meters in my SDR Panafall or on it's S-meter when it is in transmit at all. Would using a Pi tuner increase the filtering if the coax stub filter was less efficient?

Sorry if this is a really dumb question.