Humidity is the real enemy; conditioner is fine.

Yes to both — humidity can degrade the leather faster, but conditioner won’t mess with tracking if you apply it right.

Leather is porous and will absorb moisture from the air if your room is humid. Over time that can cause the surface to swell, warp, or even grow mold. The mousepad’s gliding surface changes, and not in a good way. A dehumidifier or a silica pack in your desk drawer helps more than any conditioner ever will.

As for conditioner: a light coat, let it soak in, then buff it dry — your mouse won’t notice. Optical and laser sensors read the texture of the surface, not chemical oils. The key is not leaving it greasy. Wipe off any excess and give it a few hours to cure. I’ve done this on a few leather pads and tracking stayed smooth. Just don’t drown it.

Conditioner every six months is plenty. Humidity control year-round is the better investment.