does cartridge output level affect surface noise?

Yes, and no.

Some surface imperfections can cause extremely fast or large stylus displacements, which will send unnaturally fast and large transient signals to the phono. If your cartridge is already near (or above) the design headroom of the stage, such excessive transients could cause a (momentary) overload, resulting in distortion or over-amplification of the transient.

This effect will be less true with really good phono stages like yours, but the general principle is the same.

OTOH, the mere fact of changing to a HO from a LO output version of the same cartridge means that all else is NOT the same. HO cartridges produce slower transients and lower peak amplitudes than their LO twins (all else being equal of course!). This would somewhat ameliorate the effect described above.

The net result from these two conflicting factors will depend on the individual components involved. So the best answer to your question is, "It depends."

;-)

If you use a higher output cartridge, however, your preamp and therefore your ultimate sound would probably sound better. The less your preamp has to work, the better it sounds.

That's certainly true with lower quality phono stages. But the faster transient response and greater dynamic extension of a low output cartridge easily outweigh any diminution in sound quality caused by pulling more gain from a really good phono stage (like the OP's).

That isn't just theory. It's born out by our own A/B comparisons of LO vs. HO MC's, both Benz's and ZYX's, using a top class phono stage. With good quality amplification, the sound quality using the more sensitive lower output version of a cartridge is always better.

Getting back to the original question, as Plato said, the LO cart he's using now will rarely if ever overload his phono inputs. The HO version might, or might not. The only way to know is to try. Every system's gain structure and behavior when overloaded at the source is unique.