I would never use an incident reading for a distant landscape, irrespective of film. That's a choice learnt from lessons long ago. Everything is multi-spot metered, and that is the recommendation for landscapes where there is a clear difference in contrasts (shade, bright sun, or shadow, emerging sun) — very especially if you are using transparency film. Small errors in metering are inconsequential with B&W because of latitude, something which is not in abundance with E6.