This station would not just be about serving Tarporley or the Castle - the adjacent road used to be a lovely road, and is now often gridlocked in summertime with traffic heading into Chester. This would be an ideal site for a small station with an extensive car park built on the large scrapyard which can be relocated elsewhere. This could be built long before the electrification arrives.
I disagree with arguments regarding turnaround times - this should never stop progress of the railway, as that is something that could be ironed out in years to come as numbers grow and the project pays for itself. One issue that could be a problem is paths - however that stretch of line is not at saturation.