I fitted a Lekkie chainring recently to a 36v 250w Bafang 8 fun. It's well made and lightweight. The chainline is indeed 3.5mm closer to the centre line as posted by Kinninvie. The quality of the machining is superb, the stock 46t stamped steel thing was awful. The £60 for the Lekkie ring seems expensive, but I wouldn't like to make one for less! They should come down in price if demand is high enough. I bought from Brighton e Bikes on ebay. Very quick delivery.
The bike (actually my wife's) is an MBK Alloy Frame Hybrid with a standard 68mm BB and 700c wheels. The chainstays are quite long, which helps with the chainline issue. I do however find the right hand crank arm is about 8mm further from the centre line than the left hand crank. I have filed the square taper a little inside the r/h crank so that the crank now sits as snug as possible to the bottom bracket. I was able to reduce the offset by about 2mm by doing this.
It seems to me that Bafang could modify the whole unit to sit a little more centrally to improve this situation as nearly everyone mentions the chainline issue.
Having the 42t chainring fitted when combined with an 8 speed 11-34 rear cassette on 700c wheels the gearing is wide enough to cope with most road/trail conditions.