Electric power steering on the LEAF is contained in the steering column--no hydraulic pump/reservoir involved.
I don't often use Propilot on my 2019 SL Plus, but test it once in a while. It seems to have been programmed to match the characteristics of the OEM Michelin Energy Saver A/S tires. The replacement tires I use are much better quality and yield heavier steering feel. Propilot hunts under some conditions now--does not respond quickly enough to keep the car in the lane, then overcorrects until it encroaches on the opposite lane marker, then overcorrects back in the other direction. This continues until I take control to keep the car centered in the lane. It happens under various road conditions. I think the heavier steering feel of the Michelin Cross Climate 2 tires I have now (and the Bridgestone DriveGuard run flat tires I had before) track straighter so the Propilot does not apply enough steering torque to change direction initially and then overshoots in each direction trying to correct itself.
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015; traded 8/10/2019 at 82,436 miles
White LEAF 2019 SL Plus purchased 8/10/2019