My client n52 motor had similar problems cleared up when I changed the oil filter cap which was apparently letting oil past the filter and messing up the oil pressure to the vanos. If your scanner has graphing, plot vanos actual vs requested angle and see if it's keeping up with demand. Vanos sluggish response or disa sluggish response can cause the low rpm moderate load hesitation described.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)