It depends on the pressure range. If your pressure is low enough, then the signals should not affect each other, but if your pressure goes beyond a limit specific for the Quad (which a good manual should specify), the ion current gets space-charge limited and that may reduce the overall transmission of the system. Also, if you have an conversion dynode+SEV based detector system, the active area of the conversion dynode does not recover instantly, so a spot is "dead" for a brief moment after converting a molecule into an electron signal.

Another point are ion-neutral scattering processes: unless your quad is protected by a differentially pumped cryosystem like a Feulner cup, the inner part of it also fills up with the bath gas. The ions you create can then be scattered by any Ar or He atom in the quad. Since Ar and He have different cross sections, the scattering events are differently likely. For the ion beam deposition setup I used for my PhD thesis, I once calculated by primitive kinetic gas theory how much Ar pressure it would require so that the statistical expectation value for the >1m long ion track would be 1 collision with an Ar atom - if I remember correctly, for a C60+ beam my calculation yielded something like 1.x*10-4mbar Ar pressure. What I definitely remember is that when I set that calculated pressure, the C60+ current dropped from 40 nA to 1 nA, so only the collision-free C60+ ions reached the detector.