Are all of the technical specs, like output voltage, channel separation, frequency response the domain only of the stylus itself or does the cartridge itself influence it in any way?
Are you talking about MM cartridges ?
Surely you CAN’T use a stylus from one manufacturer on the cartridge from another, because each stylus designed for certain signal generator, so forget it. There is a cartridge impedance, inductance, compliance ... these parameters are different from one model to another, you can ruin the sound using mismatched stylus.
If you can't find original stylus replacement for your cartridge then you can look for JICO replacement made for your model, it is not the original stylus, but made especially for certain models of cartridges as modern replacement. JICO SAS are the best and most expensive. You will have to find your cartridge model in the list of compatible cartridges.
What cartridge are you talking about ?