Will high-porosity cloth pads mess with my mouse tracking?

Yes, especially in humid conditions or long sessions. The open weave soaks up hand sweat, causing your mouse sensor to skip, jitter, or feel sluggish. Switch to a low-porosity cloth pad (like Cordura) or a hard pad, or wipe the pad down with a dry microfiber cloth. I would not recommend a high-porosity pad for anyone who plays more than an hour at a time.